Question

A 1.0 kg block is pushed 3.0 m at a constant velocity up a vertical wall by a constant force applied at an angle of 26.0 ◦ with the horizontal, as shown in the figure. The acceleration of gravity is 9.81 m/s 2 . If the coefficient of kinetic friction between the block and the wall is 0.40, find a) the work done by the force on the block. Answer in units of J.

Answer 1

Step-by-step explanation:

a) 8.2 J

The work done by the force on the block is equal to the force multiplied by the distance moved in the direction of the force. Since the force is applied at an angle of 26.0° with the horizontal, only a component of the force is acting in the direction of motion. The component of the force in the direction of motion is equal to the magnitude of the force multiplied by the cosine of the angle between the force and the direction of motion. Therefore, the work done by the force on the block is equal to:

Work = Force x Distance x cos(26.0°)

= (1.0 kg)(9.81 m/s2)(3.0 m) x cos(26.0°)

= 8.2 J