Two friends are each driving a car down Highway 101. During a particular 10 s interval, Jodi's car moves at a constant 60 mph. During that same time interval, Julie's car transitions from a speed of 20 mph to a speed of 30 mph. Whose car has the greater acceleration?

Julie's car.

Explanation:

The acceleration of an object is equal to the rate of change of velocity. It can be given by :

Jodi's car moves at a constant 60 mph for 10 s.

Julie's car transitions from a speed of 20 mph to a speed of 30 mph for the same time interval i.e. 10 s.

For Jodi's car, the change in velocity is equal to 0. As a result, its acceleration is equal to 0 m/s².

For Julie's car,

Initial speed, u = 20 mph = 8.9408 m/s

Final speed, v = 30 mph = 13.4112 m/s

Acceleration,

It is clear that Julie's car has the greater acceleration than the Jodi's car.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.