How much work is done by gravity in causing a 24 kg rock to tumble 50m down a slope at an angle 48 degrees to the verticle, to one decimal place?
Work done is equal to , where is the force acting on the particle and is the displacement.
If I remember my mechanics correctly, then as the question is asking you the work done by gravity, it is the horizontal displacement that you are after, which is equal to .
Then as we are interested in the direction of gravity, would it be ?