From first law of motion, law of inertia, we know that an object remains in the state of rest or motion unless acted upon by an unbalanced external force. The skateboard riding down a hill when reaches the bottom slows down due to <u>frictional force </u>acting in the opposite direction. Frictional force is a contact force which acts between two surfaces against the direction of motion of one surface over the other. Here, frictional force acts <u>between skateboard and ground</u>. This reduces the speed of the skateboard and it eventually stops.
Regular electrical needs such as heat, a/c, appliances, anything that would be used regularly with electricity. Most electrical companies use gas, coal, and other nonrenewable resources to power houses. Solar power is just a renewable way of gathering power from the sun and converting it to electricity.
ans D. Substance B has a greater latent heat of vaporization than substance A.
Da ne ajuta pentru a putea citi corect lungimea ... coronită???