It's D) valid and testable.
Answer:
Distance, d = 61.13 ft
Explanation:
It is given that,
Initial speed of the car, u = 50 mi/h = 73.34 ft/s
Finally, it stops i.e. v = 0
Deceleration of the car, 
We need to find the distance covered before the car comes to a stop. Let the distance is s. It can be calculated using third law of motion as :



s = 61.13 ft
So, the distance covered by the car before it comes to rest is 61.13 ft. Hence, this is the required solution.
Sum of all forces = mass * acceleration
Ft= tension force
Fw= force of gravity (Fw= mass* acceleration of gravity which is 9.8 this only applies to force of gravity)
Ft- Fw = 0 (there is no acceleration)
Ft = Fw
Ft= m*g
Ft= 0.250kg*9.8m/s
Ft= 2.45N
Answer:31.3W
Explanation: JUST A FORMULA
P = V*V/R = 120*120/460 = 31.3W
The function is electromagnets.<span />