A box of mass m is on a rough inclined plane that has an angle θ with the horizontal. A force of magnitude F at an angle φ with the plane is exerted on the block, as shown above. As the box moves up the plane, there is a frictional force between the box and the plane of magnitude f. What is the magnitude of the net force acting on the box?

Mars moves in an elliptical orbit around the Sun, and the mass of Mars is much less than the mass of the Sun. At the instant shown above, Mars is getting farther away from the Sun. How does this affect the potential energy of the Mars–Sun system and the magnitude of Mars’s angular momentum with respect to the Sun?

What force acts between two charges of 3 μC and 8 μC if they are separated by a distance of 103 mm?

A force F is exerted on a 5 kg block to move it across a rough surface, as shown above. The magnitude of the force is initially 5 N, and the block moves at a constant velocity. While the block is moving, the force is instantaneously increased to 12 N. How much kinetic energy does the block now gain as it moves a distance of 2 m?

The inclined plane in the figure above has two sections of equal length and different roughness. The dashed line shows where section 1 ends and section 2 begins. A block of mass M is placed at different locations on the incline. The coefficients of kinetic and static friction between the block and each section are shown in the table below. Coefficient of Friction Section 1 Section 2 Static Kinetic   If the block is sliding up section 2, what is the magnitude of the force of friction that is exerted on the block by the incline?

Two identical blocks are connected to the opposite ends of the compressed spring. The blocks initially slide together on a frictionless surface with velocity v to the right. The spring is then released by remote control. At some later instant, the left block is moving at v/2 to the left, and the other block is moving to the right. What is the speed of the center of mass of the system at that instant?

Cart 1 Cart 2 Mass 5kg 1kg Average Force 15 N 15 N Change in Momentum Average Acceleration   The data in the table above were recorded during an experiment in which two carts on a frictionless one-dimensional track collide head-on. What are the values of the magnitudes of the change in momentum ∆p2 of cart 2 and the magnitude of its average acceleration a2 during the collision?

Two charges, q1 and q2, are separated by a certain distance. The ratio of charge q1 to charge q2 is 1:2. What is the ratio of the magnitude of the force on q1 to the magnitude of the force on q2?

You are given a piece of wire made of material with resistivity = 5.0 x 10-8 Ωm. The length is 100 meters, and resistance is 0.10 ohms. What is the radius of the wire?

A battery of an emf of 15 V is delivering power to an external load resistor R = 18 Ω. The terminal voltage of the battery is 12 V. What is the internal resistance of the battery?