Question

a car moving with a speed of 72 km/h is brought to rest in 10 seconds by applying brakes. find distance and acceleration.

Answer 1

Answer:

distance=720km

acceleration=64.8m/s

Explanation:

so you start by finding the formula of distance. the formula is speed multiplied by time. speed(time).in this case our speed is 72km/h and our time is 10s.distance=72km/h(10s)=720km. that is our distance.

now acceleration. im not so sure about the formula and if i did it right but i hope it is right. i did it as acceleration=change in velocity divided by time. to find the velocity you say distance over time.so the velocity would be 72 which is 720/10. from there you find the change in velocity and divide it by the time. i think the change in velocity is 648 as you say 720-72. then you say 648 divided by the time which gives you 64.8. and as for the units im not sure but i think m/s so which means you have to convert the 64.8 to m/s.

Answer 2

Answer:

-2ms^-2.

V = U + at

0 = 20 +10a

10a = -20

a =-20/10

a =-2ms^-2

This is your answer.

I Hope It Helps You.