Question

A horizontal force in used to pull a 5 kilogram cart at a constant speed of 5 meters per second across the floor as shown in the diagram. if the force of friction between the cart and the floor is 10 newtons, the magnitude of the horizontal force along the handle of the cart is?
a. 5N
b. 10 N
c. 25 N
d. 50 N

Answer 1

A cart is pulled by horizontal force such that it moves with constant velocity

So here since velocity is constant we can say that its acceleration will be ZERO

now here for zero acceleration we can say

$F_{net} = 0$

So here we will have

$F_{net} = F_{ap} - F_f = 0$

here we know that

$F_f = 10 N$

so we will have

$F_{ap} - 10 = 0$

$F_{ap} = 10 N$

so here applied force on handle will be

b. 10 N