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Explanation:

s=d/t

t= d/s

t= 2/40

t= 0.05 hr

Answer:

-4530 J

Explanation:

Given that

Mass of the car, m = 100 kg

Speed of the car at point A, v1 = 25 m/s

Speed at point B, v2 = 8 m/s

Radius of the track, r = 12 m and with respect to the origin of the center of the track, we say that y1 = -12 at point A and y2 = 12 at point B

We also know that

W(total) = W(grav) + W(other) = K₂ - K₁

Work done by the gravitational force, W(grav) = -U(grav) = mgy1 - mgy2

Kinetic Energy, K = ½mv²

Adding all together, we have

½mv₁² + mgy1 + W(other) = ½mv₂² + mgy2

½ * 100 * 25² + 100 * 9.8 * -12 + W = ½ * 100 * 8² + 100 * 9.8 * 12

50 * 625 + 980 * -12 + W = 50 * 64 + 980 * 12

31250 - 11760 + W = 3200 + 11760

19490 + W = 14960

W = 14960 - 19490

W = -4530 J

Answer:

1.53 m/s toward the beach

Explanation:

1.53 m/s toward the beach

Explanation:

The magnitude of the velocity of the runner is given by:

where

d is the displacement of the runner

t is the time taken

In this case, d=110 m and t=72 s, so the velocity of the runner is

Velocity is a vector, so it consists of both magnitude and direction: we already calculate the magnitude, while the direction is given by the problem, toward the beach.

the measure of how many a wave passes on a certain point in a certain time is

frequency

Answer:

sound water because sound is the most important electronic wave for water

Answer:

In Celsius it is 426.667

In Kevin it is 699.817

Explanation:

Answer:

a = 3.125 [m/s^2]

Explanation:

In order to solve this problem, we must use the following equation of kinematics. But first, we have to convert the speed of 90 [km/h] to meters per second.

[tex]90\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s} \\= 25 \frac{m}{s}[/tex]

[tex]v_{f} =v_{i} + (a*t)[/tex]

where:

Vf = final velocity = 25 [m/s]

Vi = initial velocity = 0

a = acceleration [m/s^2]

t  = time = 8 [s]

The initial speed is zero as the bus starts to koverse from rest. The positive sign of the equation means that the bus increases its speed.

25 = 0 + a*8

a = 3.125 [m/s^2]

Answer:

a

Explanation:

Answer: h = 2.7 R - 1.7 r

Explanation:    

normally, force is 0 at the top ;

-N - mg = - m v^2 / ( R - r )

-0 - mg = (- mv^2) / ( R-r )

mg = (mv^2) / (R - r)

g = v^2 / ( R - r ) ; ----------------equation 1

conservation of energy ;

ΔK + ΔP = 0 ;

1/2 I ω^2 + 1/2 m v^2 + mg ( h2 - h1 ) = 0 ;  

0.5 * ( 2/5 ) m r^2 * ( v / r )^2 + 0.5 m v^2 + mg ( ( 2R - r ) -h ) = 0 ;

0.5 * ( 2/5 ) m r^2 * ( v / r )^2 + 0.5 m v^2 = mg ( - 2R + r + h ) ;

0.5 * ( 2/5 )r^2 * ( v / r )^2 + 0.5 v^2 = g ( - 2R + r + h ) ;

0.5 * ( 2/5 ) v^2 + 0.5 v^2 = g ( - 2R + r + h ) ;

[ 0.5 * ( 2/5 ) + 0.5 ] v^2 = g ( - 2R + r + h ) ;-------------equation 2

from equation 1 ,  v^2 = g ( R - r ), input in equation 2

[ 0.5 * ( 2/5 ) + 0.5 ] [ g ( R - r ) ] = g ( - 2R + r + h )

[ 0.5 * ( 2/5 ) + 0.5 ] [ ( R - r ) ] = ( - 2R + r + h )

0.7 ( R - r ) = h - 2R + r

0.7R - 0.7r = h - 2R + r

solve for h

h = 0.7R + 2R - 0.7r - r

h = 2.7 R - 1.7 r

Answer:

The answer is C) Positively charged particles

Explanation:

Particles with the same charge are repelled by one another, while particles with different charges are attracted to one another.

Answer:

positively charged particles (c)

Explanation:

I got it right on Study Island

Answer:

8.5

Explanation:

to find efficiency take the ratio between the output and input

85/100=output/input

Answer:

describe three events you cannot explain about matter and energy

Explanation:

as anything that has mass and takes up space. Matter is found in 3 major states; solid, liquid and gas. ... Atoms are the smallest particle of matter. They are so small that you cannot see them with your eyes or even with a standard microscope.

Hope that helped.

Answer:

1. Different kinds of balls bounce to different heights when dropped on the same floor.

2. Sugar dissolves faster in hot milk than in cold milk.

3. Plants grow more slowly when they are not near a window.

Explanation:

PLATO/edmentum

what happens at Point C is sublimation. the increase in temperature affects the Vapour pressure soon as you can see the curve is increasing with increasing pressure there is increase in temperature that is the sublimation Curve

Answer:

what happens at Point C is sublimation. the increase in temperature affects the Vapour pressure soon as you can see the curve is increasing with increasing pressure there is increase in temperature that is the sublimation Curve.

Answer:

D. Conclusion.

Explanation:

Answer "d' no charge

Explanation:

They are as the name says neutral. They have no charge they are electrically neutral. Just as a proton is a positively charged particle and an electron carries a negative charge.

Answer:

oh I know that sounds good to me

Answer:

-28.8 × 10-19 C

Answer:

a)    F = -1.82 10⁻¹⁵ N,  b) K = 9.1 10⁻¹⁶ J

Explanation:

a) To calculate the force between the nucleus and the electrons, let's use the Coulomb equation

           F = k q Q / r²

as the nucleus occupies a very small volume compared to electrons, we can suppose it as punctual

let's calculate

          F = 9 10⁹ (-1.6 10⁻¹⁹) (79 1.6 10⁻¹⁹) / (10⁻¹⁰)²

          F = -1.82 10⁻¹⁵ N

b) they ask us for kinetic energy

let's use Newton's second law

         F = m a

acceleration is centripetal

         a = v² / r

we substitute

         F = m v² / r

         v = √ (F r / m)

         v = √ (1.82 10⁻¹⁵ 10⁻¹⁰ / 9.1 10⁻³¹)

         v = √ (0.2 10⁻¹⁶)

         v = 0.447 10⁸ m / s

kinetic energy is

          K = ½ m v²

          K = ½ 9.1 10⁻³¹ (0.447 10⁸)²

          K = 0.91 10⁻¹⁵ J

          K = 9.1 10⁻¹⁶ J

Answer:

36m

Explanation:

a = 4 m/s^2

u = 0 ( it's starting from rest )

t = 3

a=v-u/t ....... 4=(v-0)/3, v = 12m/s

Using s=d/t,

12=d/3,

d= 36m

If an object starts from rest and accelerates at a rate of 4 m/s2 for 3 seconds, then its displacement from the start position would be 44.1 meters.

There are three equations of motion given by  Newton

v = u + at

S = ut + 1/2 × a × t²

v² - u² = 2 × a × s

As given in the problem If an object starts from rest and accelerates at a rate of 4 m/s² for 3 seconds,

S = ut + 1/2 × a × t²

S = 0 + 0.5 × 9.8 × 3²

S = 44.1 meters

Thus, If an object starts from rest and accelerates at a rate of 4 m/s2 for 3 seconds, then its displacement from the start position would be 44.1 meters.,

To learn more about equations of motion here, refer to the link given below ;

brainly.com/question/5955789

#SPJ2

Given parameters:

Mass of the body  = 200g

Force on the body  = 10N

Unknown parameters:

Acceleration produced by the force  = ?

To solve this problem we must first define force in terms of mass and acceleration. This is possible due to the Newton's first law of motion.

  Force  = mass x acceleration

Here the unknown is acceleration and we can easily solve for it.

But we must take the mass to kilogram in order for it to cancel out.

        1000g  = 1 kg

        200g  = x kg =   [tex]\frac{200}{1000}[/tex]   = 0.2kg

Now input the parameters and solve;

         10  = 0.2 x acceleration

   Acceleration  = [tex]\frac{10}{0.2}[/tex]   = 50m/s²

The acceleration produced by the body is 50m/s²

Answer: -50N

Explanation:

Newton's 3rd law says that for every force applied, there is an opposite force with equal magnitude. The person pushing on the tree will experience a force of -50N

Answer:

a) the astronauts and the station are in free fall towards the center of the Earth

Explanation:

Weightlessness is only a sensation of zero weight, a body experiences when it is in free fall towards the center of the Earth, caused by lack of contact force on such body.

Weightlessness doesn't mean the object has zero actual weight, is just a sensation of no weight due to lack of contact force to produce upward reaction on the object which gives the real sense of ones weight.

Thus, the astronauts experience apparent weightlessness because:

a) the astronauts and the station are in free fall towards the center of the Earth.

Explanation:

When load is connected to axle and effort is on the wheel it acts as first class lever with in fulcrum in the middle ..So wheel and axle is continuous lever

Answer:

10,200 N

Explanation:

Given:

Mass of the car m = 1200 kg

Acceleration of the car a = 8.5 m/s^2

Force F=?

[tex]\because F = ma\\

\therefore F = 1200 \times 8.5\\

\therefore F = 10,200 N \\ [/tex]

Answer:

answer A is the correct one

Explanation:

Weber's law states that  "the smallest discernible change of a stimulus and proportional to the stimulus".

Applying this law to cases of optical intensity, the ratio must be

          k = cte = ΔI / I

where ΔI is the variation of the intensity and I is the value of the intensity

In general, for humans, the constant is 0.15 for the rods and 0.015 for the cones of the retina.

When reviewing the answers, answer A is the correct one, since in order for the previous relationship to be maintained, the magnitudes must rise proportionally