Answer:
v = 0.92 c
Explanation:
Here, we will use the time dilation formula from Einstein's theory of relativity to find the speed of traveling of the friend:

where,
v = speed of traveling = ?
c = speed of light
t = time of return = 10 years
t₀ = time passed on earth = 4 years
Therefore,

<u>v = 0.92 c</u>
Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2.
Answer:
10N
Explanation:
1. Every Action has an equal and opposite reAction.
2. If 10N of force is acted upon an wrench, then the wrench will react with an equal amount of force, but in the opposite direction.
Explanation:
Given that,
Electric field = 5750 N/C
Charge 
Distance = 5.50 cm
(a). When the charge is moved in the positive x- direction
We need to calculate the change in electric potential energy
Using formula of electric potential energy



Put the value into the formula


The change in electric potential energy is 
(b). When the charge is moved in the negative x- direction
We need to calculate the change in electric potential energy
Using formula of electric potential energy



Put the value into the formula


The change in electric potential energy is 
Hence, This is the required solution.
Answer:
D. The period would decrease by sqrt (2)
Explanation:
The period of a mass-spring system is given by:

where
m is the mass
k is the spring constant of the spring
If the spring constant is doubled,
k' = 2k
So the new period will be

So the correct answer is
D. The period would decrease by sqrt (2)