A 75 kg man stands in an elevator. What will be the force that the elevator exerts on him when
a) the elevator is at rest? ;
b) the elevator is moving upwards with a uniform acceleration of 3.2 m/s"?
c) moving downwards with an acceleration of 2.0 m/s ?

Answers

Answer 1

Answer:

a is the answer I think so


Related Questions

______ is a disease in which the body does not produce or probory use inslin

Answers

Answer:

Diabetes

Explanation:

Insulin is an important hormone that helps the body convert sugar, starches, and other foods into energy.

Playing with a stress ball you squeeze it as
hard as you can. How does this affect the
density of the ball?

Answers

Answer:

it dies

Explanation:

MWUAHHAHAHHA

Researchers have measured the acceleration of racing greyhounds as a function of their speed; a simplified version of their results is shown in (Figure 1). The acceleration at low speeds is constant and is limited by the fact that any greater acceleration would result in the dog pitching forward because of the force acting on its hind legs during its power stroke. At higher speeds, the dog's acceleration is limited by the maximum power its muscles can provide.

How far does the dog run until its speed reaches 4.0 m/s?

Answers

[tex]\Huge\boxed{\boxed{\dfrac{4}{5}\ \text{meters}}}[/tex]

Let's start by finding the time it takes for the dog to reach a velocity of [tex]4[/tex] m/s.

We can use the following equation, where [tex]v_i[/tex] is initial velocity, [tex]v_f[/tex] is final velocity, [tex]t[/tex] is time, and [tex]a[/tex] is acceleration.

[tex]v_f-v_i=at[/tex]

We're trying to solve for [tex]t[/tex] first, so divide both sides by [tex]a[/tex].

[tex]\dfrac{v_f-v_i}{a}=t[/tex]

Substitute in the known values.

[tex]\dfrac{4-0}{10}=t[/tex]

[tex]\dfrac{4}{10}=t[/tex]

[tex]\dfrac{2}{5}=t[/tex]

Now, we can use the following formula to find the distance.

[tex]s=v_it+\dfrac{1}{2}at^2[/tex]

Substitute in the known values.

[tex]s=0*\dfrac{2}{5}+\dfrac{1}{2}*10*(\frac{2}{5})^2[/tex]

Anything multiplied by [tex]0[/tex] is

[tex]s=\dfrac{1}{2}*10*(\frac{2}{5})^2[/tex]

Just simplify from there.

[tex]s=\dfrac{1}{2}*10*\dfrac{4}{25}[/tex]

[tex]s=5*\dfrac{4}{25}[/tex]

[tex]s=\dfrac{20}{25}[/tex]

[tex]s=\boxed{\dfrac{4}{5}}[/tex]

Hey there!

The hind legs of the dog create it to accelerate.

We know the mass of the dog is 36km (m).

We know that the acceleration of the dog it 10m/s² (a).

Find the average force with the formula [ f = ma ] where m = mass and a = acceleration.

f = 36*10

f = 360 newtons

We don't know the traveled distance but we do know that the starting speed of the dog was 0m/s and the ending speed was 4m/s.

We can use the formula [ vf² = vo² + 2ad ] where vf = final speed, vo = starting speed, a = acceleration, and d = distance.

We know all the variables except the distance, so we are going to solve for d.

(4)² = (0)² + 2(10)(d)

16 = 0 + 20d

16 = 20d

16/20 = 20d/20

0.8 = d

Therefore, the dog runs 0.8 meters until it reaches 4m/s.

Best of Luck!


Change in Energy Quick Check
1 of 5
Which change occurs as an object falls toward the surface of Earth? (1 point)
The force of gravity on the object decreases.
The potential energy of the object decreases.
The acceleration due to gravity decreases.
The kinetic energy of the object decreases
IF SOMEONE GETS THE ANSWERS TO 1-5 of quick check pls post them here

Answers

Answer:

The force of gravity on the object decreases.  (FALSE)

The potential energy of the object decreases.  (TRUE)

The acceleration due to gravity decreases.  (FALSE)

The kinetic energy of the object decrease (FALSE)

Explanation:

FORCE OF GRAVITY:

Force of gravity on the object is the weight of object, which depends upon the mass and value of acceleration due to gravity (W = mg). Since, the value mass is constant on Earth and acceleration due to gravity is also constant on earth.

Therefore, force of gravity remains same on the object. The statement is false.

POTENTIAL ENERGY:

Potential energy of object depends upon the mass, value of acceleration due to gravity, and change in height of object (P.E = mgΔh). Since, the value mass is constant on Earth and acceleration due to gravity increases as the object moves towards the surface of earth. But, the height of object is decreasing.

Therefore, potential energy of object decreases. The statement is true.

ACCELERATION DUE TO GRAVITY:

Acceleration due to gravity depends upon the altitude (gh = g[1 - 2h/Re]). Since, the height of object is decreasing.

Therefore, acceleration due to gravity increases. The statement is false.

But, this change is not significant.

KINETIC ENERGY:

Kinetic Energy of object, which depends upon the mass and velocity of the object (K.E = mv²/2). Since, the value mass is constant on Earth and velocity increases as the object moves towards the surface of earth.

Therefore, kinetic energy of the object also increases. The statement is false.

As the object falls towards the surface of the earth, the potential energy of the object decreases.

The earth is a large gravitational field. The potential energy of an object is dependent on its height. As a body falls through a height, its mass remains constant but its height decreases therefore its potential energy decreases also.

Hence, the true statement is that as the object falls towards the surface of the earth, the potential energy of the object decreases.

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Help pls it’s urgent

Answers

Answer:

A

Explanation:

Refraction

refraction
explanation: refraction is the bending of light as it passes from one medium into another.

write .00000023 in scientific notation

Answers

Answer: 2.3 x 10^-7

Explanation:

When you move the decimal to the right, you decrease the exponent. So lets count how many spots you have to move the decimal spot to get an answer between 1 and 10. I counted seven spots.

So:

[tex]2.3 *10^-^7[/tex]

2.3 * 10 °−7

The degree indicates that the number is that small thing that floats above

PLZ EXPLAIN AND I WILL GIVE YOU BRANILEST

How do two interacting objects exert equal and opposite forces on each other when they collide, even though they have different masses?

Answers

Answer:

Did a little research.

Explanation:

The Law of Action-Reaction:

Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum). According to Newton's third law, the forces on the two objects are equal in magnitude. While the forces are equal in magnitude and opposite in direction, the accelerations of the objects are not necessarily equal in magnitude. In accord with Newton's second law of motion, the acceleration of an object is dependent upon both force and mass. Thus, if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.Consider the collision between the club head and the golf ball in the sport of golf. When the club head of a moving golf club collides with a golf ball at rest upon a tee, the force experienced by the club head is equal to the force experienced by the golf ball. Most observers of this collision have difficulty with this concept because they perceive the high speed given to the ball as the result of the collision. They are not observing unequal forces upon the ball and club head, but rather unequal accelerations. Both club head and ball experience equal forces, yet the ball experiences a greater acceleration due to its smaller mass. In a collision, there is a force on both objects that causes an acceleration of both objects. The forces are equal in magnitude and opposite in direction, yet the least massive object receives the greatest acceleration.

Consider the collision between a moving seven ball and an eight ball that is at rest in the sport of table pool. When the seven ball collides with the eight ball, each ball experiences an equal force directed in opposite directions. The rightward moving seven ball experiences a leftward force that causes it to slow down; the eight ball experiences a rightward force that causes it to speed up. Since the two balls have equal masses, they will also experience equal accelerations. In a collision, there is a force on both objects that causes an acceleration of both objects; the forces are equal in magnitude and opposite in direction. For collisions between equal-mass objects, each object experiences the same acceleration.

3 Points
The half-value layer for lead for g rays from 60Co is 12.8 mm. An electrometer gave a count rate of 35 pulses per second when at a
certain distance from a source, with no lead between source and detector. If 6 mm of lead were then inserted between source and
detector, the count rate (in pulses per second) would be nearest to:
A. 16
OB. 8
OC. 20
D. 25
OE. 75

Answers

Answer:

  D.  25

Explanation:

The number of pulses per second (p) for x mm of lead can be modeled by the exponential equation ...

  p = 35(0.5^(x/12.8))

Then for x=6, the value of p is ...

  p = 35·0.5^(6/12.8) ≈ 25.29

The expected count rate would be nearest 25 pps.

please help me with this physics problem​

Answers

Answer:

It says the answer. (5 marks.)

Explanation:

The FitnessGram Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. A single lap should be completed each time you hear this sound. Remember to run in a straight line, and run as long as possible.

25° 20' 42" S 131° 2' E
1. What is the place?

Answers

That place is the "Uluru- Kara That National Park"

list of energy changes when hydroelectricity city is made​

Answers

Answer:

A turbine and generator produce the electricity

Explanation:

"A hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator converts this mechanical energy into electricity.

why bananas are curved

Answers

Because they built:different

they are bananas and bananas are curved because they grow curved

An airplane flies with a constant speed of 540 miles per hour. How far can it travel in 1 1/4 hours?

Answers

Answer:

Hey!

Your answer is 675 MILES!

Explanation:

Using the S = D x T formula...

We first need to convert any values... 1 1/4 hours--75 mins (1.25hrs)

So now we substitute into the formula!

D (distance)= 540 x 1.25 = 675     (Distance = Speed x Time)

Distance Travelled= 675 MILES!

I HOPE THIS HELPED YOU!

A 20-kg bicycle carrying a 50-kg girl is traveling with a kinetic energy of 2,290 J.
What is the velocity of the girl and bicycle?
8 m/s
16 m/s
64 m/s
4 m/s

Answers

Answer:

64 m/s

Explanation:

64m/s is the answer of question

64/m/s the answer

If a bird applies a 5 N upward force on a branch to lift the branch of ground to a
height of 24 m, how much work did the bird do?

Answers

Work equals Force times Distance. 5*24= 120

A 12,000-N car is raised using a hydraulic lift, which consists of a U-tube with arms of unequal areas, filled with oil with a density of 800 kg/m3 and capped at both ends with tight-fitting pistons. The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm. The car rests on the piston on the wider arm of the U-tube. The pistons are initially at the same level. What is the force that must be applied to the smaller piston in order to lift the car after it has been raised 1.20 m

Answers

Answer:

The answer is below

Explanation:

Pascal's law states that pressure is exerted in all parts of a static fluid equally.

The area of the narrower arm with a radius of 0.05 m (5 cm) is given as:

Area of narrow arm = π(0.05)²

The area of the wider arm with a radius of 0.18 m (18 cm) is given as:

Area of narrow arm = π(0.18)²

The ratio if the wider arm area to the narrow arm area = π(0.18)² / π(0.05)² = 12.96

To move the 12000 N car, the amount of force needed = 12000/12.96 = 926 N

What type of climate would be near cold ocean currents? PLEASE HELP QUICK!!

Answers

Answer:

hot humid with lots of rain.

Explanation:

ocean currents act as conveyer belts of warm and cold water sending heat to the polar regions and helping the tropical areas cool off, thus influencing both weather and climate. the tropics are particularly rainy because heat absorption , and thus ocean evaporation, is highest.

Mild with cooler weather than similar latitudes type of climate would be near cold ocean currents.

What is cold ocean currents?

On the eastern side of ocean basins, lower latitudes or the tropics are where cold currents migrate in a direction toward the equator. They carry cold water into regions of the continent that have warm water, which are usually found on the west coastlines.

The Labrador Ocean Current and East Greenland Current flows are two noteworthy examples of cold currents.

From the perspectives of ecology and climate, ocean currents are also advantageous. For example, they are responsible for changing global temperatures.

Learn more about cold ocean currents here:

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How many atoms of each element are in 4Na3PO4?

A.) 3 sodium, 1 phosphorus, 4 oxygen
B.) 4 sodium, 4 phosphorus, 4 oxygen
C.) 12 sodium, 1 phosphorus, 4 oxygen
D.) 12 sodium, 4 phosphorus, 16 oxygen

Answers

D) 12 sodium, 4 phosphorus, 16 oxygen

sodium: 4Na3 -> 4 • 3 = 12

phosphorus: 4P - > 4

oxygen 4O4 -> 4 • 4 = 16

(the four is from the four in front of the whole formula)

Answer:

D) 12 sodium, 4 phosphorus. 16 oxygen

Explanation:

there is a four in front of the full formula, so you multiply all of the sub numbers by 4

what are the answers to the question

Answers

Answer: the link isnt loading

please help me. i have 2 hours

Answers

the missing word is clockwise moment. I hope this helps good luck

1
A truck increases its speed from 15 m/s to 60 m/s in 15 s. Its acceleration is

Answers

Acceleration = (Vf - Vi)/t
Since Vf= 60m/s
Vi= 15m/s
T= 15s
=> a= (60m/s - 15m/s)/15s
= 3
So the acceleration is 3m/s^2


3 A stationary car accelerates uniformly
for 20 s. Its velocity reaches 80
km h-1. What is the acceleration of the
car during this period?-

A 1.11 ms-2
B 2.22 ms-2
C 4.00ms-2
D 22.2ms-2​

Answers

22.2ms-2 because it jsut is

Electrically neutral objects become___when they or lose electrons.

Answers

If they lose an electron, that means they become more positive since an electron is negatively charged. So the answer is ‘positive’

Answer: positively charged

Explanation: basically when a neutral atom gets some electrons it becomes negatively charged and when a neutral atom loses elections it's positively charged Ik science is weird lol.

I hope this was the answer you were looking for.

What is magnetic poles always come in pair

Answers

Like poles repel and unlike poles attract. Magnetic poles always occur in pairs of north and south—it is not possible to isolate north and south poles.
because it just does my guy

How many sets of planets would you need to create the mass of the Sun?

Answers

Answer:

volume about 1.3 million Earths could fit inside the Sun the mass of the Sun is 1.989 X 10 to the 30 kg about 333000 times the mass of the Earth

Explanation:

step-by-step explanation hope this answer your question

A block of mass 12.2 kg is sliding at an initial velocity of 6.65 m/s in the positive x-direction. The surface has a coefficient of kinetic friction of 0.253. (Indicate the direction with the signs of your answers.)
a.) What is the force of kinetic friction (in N) acting on the block?
(b What is the block's acceleration (in m/s2)?

(c) How far will it slide (in m) before coming to rest?

Answers

Explanation:

Given that,

Mass of the block, m = 12.2 kg

Initial velocity of the block, u = 6.65 m/s

The coefficient of kinetic friction, [tex]\mu_k=0.253[/tex]

(a)The force of kinetic friction is given by :

[tex]f=\mu_k mg[/tex]

mg is the normal force

So,

[tex]f=0.253\times 12.2\times 9.8\\\\f=30.24\ N[/tex]

(b) Net force acting on the block in the horizontal direction,

f = ma

a is the acceleration of the block

[tex]a=\dfrac{f}{m}\\\\a=\dfrac{30.24}{12.2}\\\\a=2.47\ m/s^2[/tex]

(c) Let d is the distance covered by the block before coming to the rest. Using third equation of motion as follows :

[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{-(6.65)^2}{2\times 2.47}\\\\d=-8.95\ m[/tex]

Hence, this is the required solution.

This question involves the concepts of the frictional force, Newton's second law of motion, and the equations of motion.

a) The force of kinetic friction acting on the block is "-30.28 N".

b) The acceleration of the block is "-2.48 m/s²".

c) The block will slide "8.9 m" before coming to rest.

a)

The kinetic friction force is given by the following formula:

[tex]F=\mu_k mg[/tex]

where,

F = frictional force = ?

[tex]\mu_k[/tex] = coefficient of kinetic friction = 0.253

m = mass of block = 12.2 kg

g = acceleration dueto gravity = 9.81 m/s²

Therefore,

[tex]F=(0.253)(12.2\ kg)(9.81\ m/s^2)[/tex]

F = - 30.28 N (negative sign due to resistive force)

b)

According to Newton's Second Law of Motion:

F = ma

[tex]a=\frac{F}{m} = \frac{-30.28\ N}{12.2\ kg}\\\\[/tex]

a = -2.48 m/s² (negative sign due to deceleration)

c)

Using the third equation of motion to calculate the distance:

[tex]2as=v_f^2-v_i^2[/tex]

where,

s = distance = ?

vf = final speed = 0 m/s

vi = initial speed = 6.65 m/s

Therefore,

[tex]2(-2.48\ m/s^2)s=(0\ m/s)^2-(6.65\ m/s)^2\\\\s=\frac{-(6.65\ m/s)^2}{2(-2.48\ m/s^2)}[/tex]

s = 8.9 m

Learn more about Newton's Second Law of Motion here:

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The attached picture shows Newton's Second Law of Motion.

Temperature is a measure of

Answers

Answer:

The average kinetic energy

The amount of heat a substance has or the average kinetic energy of particles in a substance

4. A tankful of liquid has a volume
of 0.2m3. What is the volume in (a)
lities (b) cm3 (c)ml​

Answers

Explanation:

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A compass needle moves when it is near a wire with electric current. which of the following explains this phenomenon?

Answers

Answer:

D

Explanation:

Your chosen answer is correct .

Hope this helps :)

The electric current creates a magnetic field that explains this phenomenon. So, the correct option is D.

What is Magnetic field?

A magnetic field is defined as the vector field that describes the magnetic effect on electric charges, electric currents and magnetic materials where a charge moving in a magnetic field experiences a force perpendicular to its velocity and magnetic field.

The magnetic field is explained as the region around a magnet that has a magnetic force where all magnets have north and south poles. Opposite poles attract each other, while like poles repel each other. The electric current creates a magnetic field that explains a compass needle moves when it is near a wire with electric current phenomenon.  

Therefore, the correct option is D.

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What is the product of 0.0322 cm x 6.5 cm rounded to the correct number of significant figures?

Answers

Answer:

2.093 × 10⁻³ cm²

Explanation:

Given:

0.0322 cm × 6.5 cm

Find:

Product

Computation:

⇒ 0.0322 cm × 6.5 cm

⇒ 0.2093 cm²

2.093 × 10⁻³ cm²

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