Question

A body starts with a velocity of 40m s-1 and moves with an acceleration of 10m s-2 the distance traveled by the body in 15 seconds and the velocity at the end of the 15th second is

Answer 1

Explanation:

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