Question

A car starts from an initial velocity of 10m/s and accelerates at 2.5m/s².how long will it take the car to reach a speed of 40m/s.. How far doea the car travel during this time?

Answer 1

a=(v-u)/t
We know a=2.5, v=40, u=10, so:
2.5=(40-10)/t
2.5t=40-10
2.5t=30
Divide both sides by 2.5
t=12 It takes 12 seconds for the car to reach 40m/s

To find out how far it went, you do:
d=v+1/2 at^2
d=10+1/2(2.5)(12)^2
d=10+1/2(2.5)(144)
d=10+(1.25)(72)
d=10+90
d=100m

Hope this helps :)