Question

A 2.0 kg box is pulled along a frictionless, horizontal surface by a force that makes an angle of 30 degrees with the ground. If the box is pulled a distance of 4.0 meters and changes speed from 1.0 m/s to 3 m/s, what was the magnitude of the force on the box?

Answer 1

Answer:

2 N

Explanation:

v = Final velocity = 3 m/s

u = Initial velocity = 1 m/s

s = Displacement = 4 m

m = Mass of box = 2 kg

Acceleration of the box is

$v^2-u^2=2as\\\Rightarrow a=\dfrac{v^2-u^2}{2s}\\\Rightarrow a=\dfrac{3^2-1^2}{2\times 4}\\\Rightarrow a=1\ \text{m/s}^2$

Force is given by

$F=ma\\\Rightarrow F=2\times 1\\\Rightarrow F=2\ \text{N}$

The force on the box is 2 N.