151.9j
Explanation:
PE=1/2kx^2
PE=1/2(980)(.50)= 245j
PE=(1/2)(980)(.81)= 396.9j
396.9- 245= 151.9j
My guess is A. depth increases because I know that the deeper you go in the ocean, the higher the water pressure is (which makes it difficult to explore).
solution:
Weight of bucket = 10kg
Length or distance =14m
Weight of rope=0.5kg/m
At any point x of the rope,
=(0.5)(14-x)
=(7-0.5x)
Since the water finishes draining at 14m level and total weight of water is 42kg
Total mass=(7-0.5x)+(42-3x)+10=(59-3.5x)kg
Force=(9.8)(59-3.5x)

Answer:
Friction occurs because no surface is perfectly smooth.
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.