Question

A grocery cart with a mass of 15 kg is pushed at constant speed along an aisle by a force fp = 12 n which acts at an angle of 17° below the horizontal. find the work done by each of the forces on the cart if the aisle is 14 m long.

Answer 1

Given:

Mass of cart: 15kg

Aisle length = 14m

Angle = 17° below the horizontal

Force fp = 12 N

 

So, the solution would be like this for this specific problem:

 

1)    W(by applied force) = F(applied) x s x cosθ 
=>W(a) = 12 x 14 x cos17* = 160.66 J 

2)    By F(net) = F(applied) - F(friction) 
=>As v = constant => a = 0 => F(net) = 0 
=>F(applied) = F(friction) 
=>W(friction) = -F(friction) x s
=>W(friction) = -F(applied) x s 
=>W(f) = -12 x 14 x cos17* = -160.56 J 

3)    0, as the displacement is perpendicular to Force 

4)    0, as the displacement is perpendicular to Force  

To add, the force that is applied to an object by a person or another object is called the applied force.