A 20.0 kg box slides down a 12.0 m long incline at an angle of 30.0 degrees with the horizontal. A force of 50.0 N is applied to the box in the upward direction to try to prevent it from sliding down the incline. The applied force makes an angle of 10.0 degrees to the incline. If the incline has no friction, then the increase in the kinetic energy of the box is

The increase in kinetic energy is 586.32 J.

Explanation:

Force acting to push the object Down the incline = component of weight acting down the incline

Let's call this force

Force acting to push the object UP the incline = component of stopping force acting up the incline

Let's call this force

Calculating these forces we get:

The increase in the kinetic energy will be equal to the work done :

Thus, the increase in kinetic energy is also 586.32 J.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

massxgravity x heght=weightxheight= pe

4900=490xh

h=10