Answer:
The speed is 0.97 c.
Explanation:
Given that,
Dilated time t'= 50.0 years
Rest time t = 13.0 years
We need to calculate the speed
Using formula of time dilation

Where, t' = change in time
t = rest time
v = velocity
c = speed of light
Put the value into the formula




Hence, The speed is 0.97 c.
Ethylene glycol reduces the cooling efficiency of water because it has a lower heat capacity as compared to water. A substance with low heat capacity would mean that the material only needs a small amount of energy to increase its temperature. So, for ethylene glycol, the heat transfer would be faster decreasing the cooling efficiency.
Answer:

Explanation:
Let m is the mass of both cars. The first car is moving with speed v and the other car is moving with speed 2v. The only force acting on both cars is the centripetal force.
For faster car on the road,

v = 2v

..........(1)
For the slower car on the road,
............(2)
Equation (1) becomes,


So, the frictional force required to keep the slower car on the road without skidding is one fourth of the faster car.