Question

a car initially at rest picks up a velocity of 72 km/h over a distance of 25m. Calculate time​

Answer 1

Answer:

1.25 second is the answer.

Answer 2

Answer:2.5 sec

Explanation:

Vi= o ,whenever the body is at rest the velocity becomes 0

Vf= 72 km/h ,to convert km/h to m/s u have to × it by 1000 and ÷ it by 3600

S= 25m

Required:

t= ?

Formula:

2aS= Vf² -Vi² ,as u can see in first eq of motion u have to find acceleration ,which u don't have. To find 'a' u have to apply third eq of motion ,as mention in the above ,place the values in it and u'll find the value of 'a'

Then to find 't' u have to apply first eq of motion (at =Vf-Vi ) put the values in it and u'll have ur and .