Please Help - medal for help - A bus travels at 25 m/s then decelerate steadily.It comes to a complete stop in 40 seconds.What is it's acceleration ? Not sure how to find answer , can you explain it to me TY !

Question

matt101 · Answer

The question gives us the initial velocity, v(i), of the bus, as well as the time, t, it takes for the bus to come to a stop. The equation for acceleration is:

$$a={v_f-v_i \over t}$$
We have v(i) and t. The trouble is we can only solve for a if we have the final velocity, v(f), as well. The question actually does give us v(f) - remember, the bus came to a complete stop, so its final velocity must be 0 m/s! Now we can solve for a:

$$a={0-25 \over 40}=-0.625$$
So the acceleration of the bus is -0.625 m/s^2. It's negative because the bus is slowing down.

If you have any questions please ask!

anonymous · Answer

Thank you so much :) going to post another question if you would like to help again ty

matt101 · Answer

No problem