Answer:
D.
a control group
Explanation:
In a scientific experiment such as the one above, there is an experimental group and a control group. The experimental group is the group that receives the treatment while the control group does not receive any treatment. The control group helps the researcher to observe if the treatment had any significant effect.
In this case, it will help Alan and Monica to determine if fertilizer X actually had an effect on the plant. Therefore, the pot with o grams of fertilizer in it is the control group.
What is the velocity of a toy car that rolls 350 cm towards a wall in 4.8 seconds?
A. 0.73 cm/s towards the wall
B. 1,680 cm/s towards the wall
C. 354.8 cm/s towards the wal
l D. 72.9 cm/s towards the wall
Answer:
D. 72.9 cm/s towards the wall
HELP PLEASE!!!
a crane lifts a 3,000 kg beam of concrete from the ground to a height of 50 m. what work is being done on the concrete?
Answer:
1,470,000Joules
Explanation:
Work done = Force * distance moves in the direction of the force
Given
mass = 3000kg
distance = 20m
Get the force
F = mg
F = 3000(9.8)
F = 29400N
Get the work done
Work done = 29400 * 50
Work done = 1,470,000Joules
Hence 1,470,000Joules work has been done on the concrete
Which best explains how a heat pump can heat a room?
Cold air from the house is moved through pipes, where it absorbs thermal energy.
Warm air from outside is pushed into the house to replace the cold air.
Combustion warms the air when chemical energy is transferred to thermal energy.
Fuel is used to move a piston, which pushes warm air into the house.
Answer:
Cold air from the house is moved through pipes, where it absorbs thermal energy.
Explanation:
Answer:
Like your refrigerator, heat pumps use electricity to move heat from a cool space to a warm space, making the cool space cooler and the warm space warmer. ... The most common type of heat pump is the air-source heat pump, which transfers heat between your house and the outside air.
Is this helpful
There are many factors that would affect how fast a bowling ball moves. Which of the two factors listed below is most important in determining the acceleration rate of a bowling ball? A direction and time B. mass and direction C. force and direction D force and mass
Acceleration due to gravity on Planet X is 4.5 m/s2 and the weight of an astronaut is 351 N. What is the mass of the astronaut?
Answer:
312
Explanation:
Iron nail sinks in water while a ship made of iron-steel floats in it. Why ?
Answer:
because the density of iron nail is more tha n density of water but the density of ship made iron steel is less than the density of water
Kathy 82 kg performer standing on a diving board at the carnival dive straight down into a small pool of water. Just before striking the water her speed is 5.50M/S at a time of 1.65 after entering the water her speed is reduced to 1.10M/S. What is the force that acts on her when she is in the water
Solution :
Given weight of Kathy = 82 kg
Her speed before striking the water, [tex]$V_o $[/tex] = 5.50 m/s
Her speed after entering the water, [tex]$V_f$[/tex]= 1.1 m/s
Time = 1.65 s
Using equation of impulse,
[tex]$dP = F \times dT$[/tex]
Here, F = the force ,
dT = time interval over which the force is applied for
= 1.65 s
dP = change in momentum
dP = m x dV
[tex]$= m \times [V_f - V_o] $[/tex]
= 82 x (1.1 - 5.5)
= -360 kg
∴ the net force acting will be
[tex]$F=\frac{dP}{dT}$[/tex]
[tex]$F=\frac{-360}{1.65}$[/tex]
= 218 N
which diseases are most likely to be treated with antibiotics?
a. those caused by viruses
b. those caused by fungi
c. those caused by parasites
d. those caused by bacteria
Answer:
c) those caused by parasites
What happens if all the heat energy contained in a body is removed? and what will be it's temperature?Explain
Answer:
If all the heat energy contained in a body is removed and changes in its temperature is described below in detail.
Explanation:
It moves from a body at a greater temperature to a body at a cheaper temperature. All element survives as solids, liquids, or gases. The material can transfer from one station to another if warmed or cooled. When heat is provided to a body its heat increases: When a physical body, hard, liquid. When heat is provided is stopped to a body its temperature decline.
what is kepler-10b ?
Answer:
is the first confirmed terrestial planet to have been discovered outside the solar system by the kepler space telescope
Explanation:
Answer:
tumko hy matlab hai mera
1. A limiting factor for using nuclear energy is the
produced
O A. flooding
O B. pollution
O C. waste
O D. heat
Answer:
waste
Explanation:
took da test. nhgvgg
Explain what happens as an object moves through each phase of matter.
ASAP PLEASE HELP ME????????
Answer:
gas vibrate, move about freely at high speeds, liquid vibrate, move about, and slide past each other. solid vibrate (jiggle) but generally do not move from place to place
Calculate the displacement of a motorcycle that accelerates forward from rest to 7.0 m/s in 3.5 s.
I need solution and statement.
Answer:
12.25 meters
Explanation:
s=1/2(v+u)t
s= displacement
v= final velocity
u= initial velocity
t= time
7m/s+0m/s divide by 2= 3.5 m/s velocity Times 3.5 seconds= 12.25 meters
Two persons (each on a skateboard) are initially standing still and facing each other before pushing off of each other. One person (50 kg) moves backwards at 1.1 m/s. Calculate the velocity of the second person (65 kg).
Answer:
The second person will have a velocity of 0.85 m/s in the opposite direction of the first person.
Explanation:
Law Of Conservation Of Linear Momentum
The total momentum of a system of bodies is conserved unless an external force is applied. The formula for the momentum of a body with mass m and velocity v is:
P=mv.
If we have a system of bodies, then the total momentum is the sum of them all
[tex]P=m_1v_1+m_2v_2+...+m_nv_n[/tex]
If a collision occurs, the velocities change to v' and the final momentum is:
[tex]P'=m_1v'_1+m_2v'_2+...+m_nv'_n[/tex]
In a system of two masses, the law of conservation of linear momentum is:
[tex]m_1v_1+m_2v_2=m_1v'_1+m_2v'_2[/tex]
According to the conditions of the problem, two persons standing on a frictionless surface are initially at rest (v1=0, v2=0). Their masses are m1=50 Kg and m2=65 Kg. After the push, one person (say m1) moves backward at v1'=-1.1 m/s. We can calculate the speed of the other person by solving for v2':
[tex]\displaystyle v'_2=\frac{m_1v_1+m_2v_2-m_1v'_1}{m_2)[/tex]
Substituting:
[tex]\displaystyle v'_2=\frac{50*0+65*0-50(-1.1)}{65)[/tex]
[tex]\displaystyle v'_2=\frac{55}{65}[/tex]
[tex]v'_2=0.85 \ m/s[/tex]
The second person will have a velocity of 0.85 m/s in the opposite direction of the first person.
A jeep starts from rest. If its velocity becomes 72 km/hr in 4 seconds.
i. What is the acceleration of the jeep ?
[Ans: 5 m/s]
ii. What is the distance covered by jeep?
[Ans : 10 m]
Answer:
See the answers below
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o}+a*t[/tex]
But first we must convert the velocity from kilometers per hour to meters per second.
[tex]72[\frac{km}{h}]*[\frac{1000m}{1km}]*\frac{1h}{3600s} =20[m/s][/tex]
i)
Vf = final velocity = 20 [m/s]
Vo = initial velocity = 0 (stars from the rest)
a = acceleration [m/s²]
t = time = 4 [s]
[tex]20 = 0+a*4\\a=20/4\\a = 5[m/s^{2}][/tex]
ii)
Now we can calculate the distance with the following equation of the kinematics.
[tex]v_{f}^{2}=v_{o}^{2} +2*a*x[/tex]
where:
x = distance covered [m]
[tex]20^{2} =0 +2*5*x\\400=10*x\\x = 40 [m][/tex]
Calculate the current in each 10.0 Ω resistor in the series circuit and in the parallel circuit if the power supply is 60.0 V.
Answer:
Explanation:
Step one:
given data
the current in each 10.0 Ω
The power supply is 60.0 V.
Required:
current in the series and parallel circuit arrangement
Step two:
The drawing looks like a ladder with 4 rungs.
One rung is a 60-volt battery.
The other 3 rungs are the 3 resistors.
a). The equivalent resistance is the reciprocal of (1/10 + 1/10 + 1/10).
That's the reciprocal of 3/10, or about 0.3ohms.
b). I = V/R = 60 /0.3... = 200 Amperes.
Answer:
for series: i=v/r
V=60volts
R=30ohms (added ohms of the 3 resistors)
i=60volts/30ohms
i=2amps
for parallel: i=v/r1 + v/r2 ...
v=60volts
r1=10
r2=10
r3=10
i=60/10+60/10+60/10
i=6+6+6
i=187
Explanation:
https://phys.libretexts.org/Bookshelves/University_Physics/Book%3A_University_Physics_(OpenStax)/Book%3A_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)/10%3A_Direct-Current_Circuits/10.03%3A_Resistors_in_Series_and_Parallel
A key falls from a bridge that is 45 m above the water. It falls directly into a model boat, moving with constant velocity, that is 12 m from the point of impact when the key is re- leased. What is the speed of the boat
Answer:
4m/s
Explanation:
The motion is in downward direction, and the boat is moving with constant velocity, the position of the boat horizontally is 12m before the key fall.
The height difference "h"= ( y- y°)= 45 m
We can determine the needed time the key requires to reach the water using the expression from Newton's law
h= v(o) + 1/2 at^2
g= acceleration due to gravity= 9.8m/s^2
h= v(o) + 1/2 gt^2 -------------------------eqn*)
V(o)= 0 for the key= initial velocity
h= height that the key falls= 45m
If we substitute the above values into eqn(*) we have
We can make t^2 subject of the formula since v(0)= 0
t^2= h/(1/2 g)
= 45/(1/2× 9.8)
t^2= 45/4.9=9.18
t= √9.18
t=3.03 secs
Since the boat was moving with constant velocity,
Then Velocity= distance/ time
= 12/3.03
Velocity= 4m/s
Hence, the speed of the boat is 4m/s
Answer:
The person above me is correct. The speed of the boat is 3.6363m/s, or also 4m/s.
We know these following values from the key:
d = 45 , g = -9.8 (its because its falling) , vi = 0
With this, we can plug and chug using kinematic equations.
Doing so will get you 29.69 for Vf and 3.03 for time.
Now, we want the speed from the boat -- speed is defined as the distance over time. We know the distance from the boat is 12m, but now we know the time, which is 3.03.
-This time is correct because we know the boat was at "0m" when the key was at the start, but after it dropped, it was at 12m. So by finding out the time it took for the key to drop, it also tells us the amount of time it took the boat to travel 12m.
So this means we can divide 12m by 3.03s, or you can round it to 3. Whatever really works;
12/3.03 should get you something like 3.63 repeating
if you rounded, you will get 12/3, which is 4.
how do you get the net force
The net force on a body is the resultant of all the force acting on the body, which can be calculated by the vector addition of all the forces as the force is a vector quantity.
Generally, the components of the forces in a single direction (x,y, and z) added together, then the resultant of all the forces can be determined which is the net force.
For example if f1, f2,..fn are n forec action on the body as
f1 = a1 i + b1 j + c1 k
f2= a2 i + b2 j + c2 k
fn = an i + bn j +cn k
Then the net force, F, action on the body
F= f1 + f2+ ... +fn
F= (a1 i + b1 j + c1 k) + (a2 i + b2 j + c2 k)+...+(an i + bn j +cn k)
F=(a1+a2+...an)i+(b1+b2+...+bn)j + (c1+c2+...+cn)k which is the net force.
In this way, the net force can be determined.
Two sound waves (wave X and wave Y) are moving through a medium at the same speed. If wave X has a greater frequency than wave Y, then wave X
Answer:
Wave X has a shorter wavelength.
Explanation:
The relation between the speed of a wave, its wavelength and frequency is given by :
[tex]v=f\lambda[/tex]
It can be seen that the relationship between the frequency and wavelength is inverse.
In this problem, it is mentioned that two sound waves (wave X and wave Y) are moving through a medium at the same speed. The frequency of wave X is greater than wave Y. Then it would mean that wave X have shorter wavelength than wave Y (due to inverse relation).
What type of material does not transfer heat well?
O A. A thermal conductor, such as air
B. A thermal insulator, such as water
O C. A thermal conductor, such as water
OD. A thermal insulator, such as air
Answer:
insulator
Explanation:
it keeps heat in not moves it
An elevator car has a mass of 750 kg, and its three passengers have a combined mass of 135 kg. If the elevator and its passengers ride to the ground floor, 20.7 m below, find the change in gravitational potential energy of the car and its passengers. Show all your work.
Answer:
The change in gravitational potential energy is -1.80x10⁵ J.
Explanation:
The change in gravitational potential energy is given by:
[tex] \Delta E_{p} = E_{p_{f}} - E_{p_{i}} [/tex]
[tex] \Delta E_{p} = mgh_{f} - mgh_{i} [/tex]
Where:
"i" is for final and "f" for final
m: is the mass
g: is the gravity = 9.81 m/s²
h: is the height
For the car and the passengers we have:
[tex] \Delta E_{p} = m_{T}g(h_{f} - h_{i}) = (750 kg + 135 kg)9.81 m/s^{2}(0 - 20.7 m) = -1.80 \cdot 10^{5} J [/tex]
The minus sign is because when the elevator car and the passengers are up they have a bigger gravitational potential energy than when they are in the ground.
Therefore, the change in gravitational potential energy is -1.80x10⁵ J.
I hope it helps you!
__________ skids occur when you suddenly press too hard on the accelerator and the drive wheels lose traction.
Answer:
Power Skids
Explanation:
Power Skid like the question suggested, is a skid that occurs when you suddenly press too hard on the accelerator and the drive wheels lose traction. Power Skid is one of the 4 types of Skids. The other 3 includes;
Cornering skid
Blowout skid and
Braking skid.
Power skid occurs mostly as a result of insanely high speed and or acceleration,when the accelerator is pressed on too suddenly causing the vehicle to be driven beyond its capabilities, and then to skid, ultimately.
why do students in uganda need to study physics
Answer:
1.To acquire problem solving skills like simple repairs at home,simple instruction etc. 2. To acquire skills of operating and using equipments.Explanation:
I hope l helped you ❤❤❤Answer:
1. Ability of problem solving.
2. Physics gives u a job.
3. Physicists can become engineers.
4. Physics puts your math to use.
5. Physics is versatile.
6. Physics makes things possible.
Under which conditions are particles in a medium said to be in phase with one another?
A: when they have the same displacement from the equilibrium position and the same velocity
B:when they have the same frequency from equilibrium position and the same wavelength
Answer:
Corvette Corvette
Explanation:
teehee
The answer is A btw :)
When two particle have the same displacement from the equilibrium position and the same velocity, they are said to be in phase with one another.
What is phase?Phase is the location of a time point on a waveform's cycle. A phase is an dimensionless quantity. While two or more waveforms may have the same frequency, cycle, and wavelength, phase refers to how closely they are aligned.
Particles in a medium said to be in phase with one another when they have the same displacement from the equilibrium position and the same velocity. As frequency and wavelength is property of waves - not particles.
Learn more about phase here:
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two porters are available to carry a long timber wood.out of them one is weak.how to do you make less load to the weak one? write with reason.
Answer:
Please find the answer in the explanation.
Explanation:
Given that two porters are available to carry a long timber wood.out of them one is weak. how do you make less load to the weak one?
We can make the weak one to carry less load through two different ways or means.
First, if we can locate the centre of gravity and centre of mass of the long timbre wood, the week one can carry the other end away from the center of gravity and centre of mass.
Second, the strong porter can carry the long timbre wood almost to the fulcrum and allow the weak one to support at the other end. By doing this, the weak one will only carry light portion of the load.
write the chemical name and chemical formula for four hydrogens and two nitrogen
Answer:
2 moles of H2Nsuperscript(-) or NHsubscript2 , amide group!
I hope it will be useful.
When we dissolve a substance in water, a -------- is formed
Answer:
solution
Explanation:
Answer:
When a substance dissolves in water, you can’t see it anymore, it’s still there, but has mixed with the water to make a transparent liquid called a solution. The bonds in salt compounds are called ionic because they both have an electrical charge—the chloride ion is negatively charged and the sodium ion is positively charged.
Explanation:
I need help asap :>
Answer:
[tex]\huge\boxed{\sf v = 0.75\ m / s}[/tex]
Explanation:
Given Data:
Wavelength = λ = 0.25 m
Frequency = f = 3 Hz
Required:
Speed = v = ?
Formula:
v = fλ
Solution:
v = (3)(0.25)
v = 0.75 m / sec
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807A kayak took 5 hours to finish its trip on a river. If it traveled at an
average speed of 18 mph (mile per hour), what was the distance of the
trip?
miles
The distance of the trip that Kayak travelled at an average speed of 18 mph in 5 hour is 90 miles
How do I determine the distance?First, we shall obtain the eqaution to determine the distance. This can be obtained as follow:
Speed is defined as:
Speed = distance / time
Cross multiply
Distance = speed × time
With the above formula, we can obtain the distance. Details below
The following data were obtained from the question:
Time = 5 hourSpeed = 18 mphDistance =?Distance = speed × time
Distance = 18 × 5
Distance = 90 miles
From the above calculation, we conclude that the distance traveled is 90 miles
Learn more about distance travelled:
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What force is represented by vector a
Answer:
velocity
Explanation:
Velocity represents the direction of an object with a specified speed