Answer:
It is positive and smaller in magnitude than the initial acceleration.
Explanation:
We know that acceleration is defined as the change of velocity in a given time.
We see that the time interval is equal to 30 seconds (70 - 40). In this interval we also see that the velocity increases from 245 to 250 (m/s) approximately. Therefore the acceleration is positive.
With respect to the magnitude we can say that it is smaller than at the beginning since the change of velocities is smaller with respect to the change of velocities at the beginning.
A shopping cart that starts from rest, is accelerated for 4 s, moves at constant velocity for 4 s, and is decelerated for 4s until returning to rest, has an average acceleration of 0 m/s².
A shopper is pushing a cart down a grocery store aisle. The movement of the cart is:
- It starts from rest.
- From t = 0 s to t = 4.0 s it is accelerated with a constant force.
- From t = 4 s to t = 8.0 s it receives just enough force to balance the friction on the cart.
- From t = 8 s to t = 12 s it is decelerated until it comes to rest.
All in all, at the initial time (t = 0 s), the velocity is 0 m/s (rest) and at the final time (t = 12 s) the velocity is 0 m/s as well (rest). The average acceleration in that period is:

A shopping cart that starts from rest, is accelerated for 4 s, moves at constant velocity for 4 s, and is decelerated for 4s until returning to rest, has an average acceleration of 0 m/s².
Learn more: brainly.com/question/16274121