Question

A grocery cart with a mass of 20 kg is pushed at constant speed along an aisle by a force F = 12 N. The applied force acts at a 20° angle to the horizontal.

Find the work done by each of the forces on the cart if the aisle is 18 m long.

Answer 1

Step-by-step explanation:

Given

mass of cart m=20 kg

Force applied F=12 N at angle of
`\theta =20^(\circ)` with horizontal

Force can be resolved in two components i.e.
`F\cos \theta`and
`F\sin \theta`

`F\sin \theta`is will act Perpendicular to the motion of cart and
`F\cos \theta`will help to move the cart .

Since cart is moving with constant velocity therefore net force is zero on the cart as friction is opposing the
`F\cos \theta`

Work done by
`F\cos \theta`is

`W_1=F\cos \theta \cdot L`

`W_1=12\cos (20)\cdot 18=202.978 J`

Work done by Friction will be same but in Opposite Direction

`W_f=-202.978 J`

Work done by
`F\sin \theta` is

`W_2=0` because direction of force and motion is Perpendicular to each other.