Power in physics is work done over time. So the answer is Power is the rate at which work is done.
Answer:
The magnitude of the electric field are
and 
Explanation:
Given that,
Radius of inner shell = 11.0 cm
Radius of outer shell = 14.0 cm
Charge on inner shell 
Charge on outer shell 
Suppose, at r = 11.5 cm and at r = 20.5 cm
We need to calculate the magnitude of the electric field at r = 11.5 cm
Using formula of electric field

Where, q = charge
k = constant
r = distance
Put the value into the formula


The total charge enclosed by a radial distance 20.5 cm
The total charge is

Put the value into the formula


We need to calculate the magnitude of the electric field at r = 20.5 cm
Using formula of electric field

Put the value into the formula


Hence, The magnitude of the electric field are
and 
Answer: 4.8 s
Explanation:
We have the following data:
the mass of the raft
the force applied by Sawyer
the raft's final speed
the raft's initial speed (assuming it starts from rest)
We have to find the time 
Well, according to Newton's second law of motion we have:
(1)
Where
is the acceleration, which can be expressed as:
(2)
Substituting (2) in (1):
(3)
Where 
Isolating
from (3):
(4)
Finally:
True because the kind of light we get is white light and everything we see is actually every colour except the color we are seeing because that is wwhat is reflected
Explanation:
Given that,
Mass of a freight car, 
Speed of a freight car, 
Mass of a scrap metal, 
(a) Let us assume that the final velocity of the loaded freight car is V. The momentum of the system will remain conserved as follows :

So, the final velocity of the loaded freight car is 0.182 m/s.
(b) Lost on kinetic energy = final kinetic energy - initial kinetic energy
![\Delta K=\dfrac{1}{2}[(m_1+m_2)V^2-m_1u_1^2)]\\\\=\dfrac{1}{2}\times [(30,000+110,000 )0.182^2-30000(0.85)^2]\\\\=-8518.82\ J](https://tex.z-dn.net/?f=%5CDelta%20K%3D%5Cdfrac%7B1%7D%7B2%7D%5B%28m_1%2Bm_2%29V%5E2-m_1u_1%5E2%29%5D%5C%5C%5C%5C%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%20%5B%2830%2C000%2B110%2C000%20%290.182%5E2-30000%280.85%29%5E2%5D%5C%5C%5C%5C%3D-8518.82%5C%20J)
Lost in kinetic energy is 8518.82. Negative sign shows loss.