Question

A body starts from rest and its velocity increases to 40 m/s in 5 s. Find acceleration of the body.​

Answer 1

Answer:

8

Explanation:

Answer 2

Answer:

A body starts with a velocity of 40m/s and moves with an acceleration of 10m/s². How would one find the distance travelled by the body in 15 seconds and the velocity at the end of 15 seconds?

Use kinematics to form an equation, and then just solve for d:

d = Vit + 1/2at^2

d = (40)(15) + 1/2(10)(15)^2

d = 1725 m

For the velocity, use another kinematic equation:

Vf^2 = Vi^2 + 2ad

Vf = sqrt(Vi^2 + 2ad)

Vf = sqrt((40)^2 + 2(10)(1725))

Vf = 190 m/s

Alternatively, if you know some very basic calculus, you could look at the first equation’s derivative which would give you velocity as a function of time:

d/dx( s(t) = Vit + 1/2at^2)

V(t) = Vi + 1/2(2)at

V(15) = 40 + (10)(15)

V(15) = 190 m/s

Which I believe is a more elegant way of showing it!