Please help In which situations (1-5) the internal energy of the body changes as a result of work (A), and in which - as a result of heat flow (B)? Mark the correct squares.
1. The bullet hit the shield.
2. People sitting by the hot fireplace felt warm.
3. The stone statue, standing in a sunny place, warmed up on one side.
4. The metal ball was thrown into hot water.
5. While braking the car's tires warmed up

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.