66.2k views
12 votes
A car is coasting backwards downhill at a speed of 3.0 m/s when the driver gets the engine started. After 2.5

s, the car is moving uphill at 4.5 m/s. Assuming that uphill is positive direction, what is the car's average
acceleration.

User Rpbaltazar
by
4.6k points

1 Answer

12 votes

Answer:

0.6m/s²

Step-by-step explanation:

Given parameters:

Initial velocity = 3m/s

Final velocity = 4.5m/s

Time taken = 2.4s

Unknown:

Average acceleration = ?

Solution:

To solve this problem, we use the expression:

Acceleration =
(v - u)/(t)

v is the final velocity

u is the initial velocity

t is the time taken

Acceleration =
(4.5 - 3)/(2.5) = 0.6m/s²

User Bastien Caudan
by
4.2k points