Question

.. An object (mass 10.0 kg) slides upward on a slippery

vertical wall. A force F of 60 N acts at an angle of 60° as
shown in Fig. 4.36.
(a) Determine the normal force
exerted on the object by the wall.
(b) Determine the
object's acceleration.

Answer 1

(a) The normal force exerted on the object by the wall is 0 N

(b) The acceleration of the object is 4.6 m/s² downwards.

How to calculate the normal force?

(a) The normal force exerted on the object by the wall is calculated as follows;

Fn = mg cosθ

where;

• m is the mass of the object
• g is acceleration due to gravity
• θ is the angle of inclination of the object

Fn = 10 kg x 9.8 m/s² x cos (90)

Fn = 0 N

(b) The acceleration of the object is calculated by applying newton's second law of motion as follows;

F(net) = ma

F sinθ - mg = ma

60 x sin(60) - (10 x 9.8) = 10a

-46.03 = 10a

a = -4.6 m/s²