If the velocity of a car changes from 20 meters per second (m/s) to 60 m/s in 4 seconds, what is the acceleration over that 4 second period?
m/s2

10 m/s^2

Explanation:

Let,

u-> initial velocity = 20m/s

v-> final velocity = 60m/s

t-> time = 4s

a-> acceleration

u = 20m/s

v = 60m/s

t = 4s

Using Velocity - Time relation,

v = u + at

=> v - u = at

=> (v - u)/t = a

=> a = (v-u)/t

=> a = (60-20)/4

=> a = 40/4

=> a = 10 m/s^2

the answer is yes

it has kinetic energy

reason

an object has kinetic energy when you stop the force carrying it, the object will stay in motion.

hope this contact me for more questions if you'd like: )