Twin sisters Annie and Hannah are fighting

over their favourite toy. Annie pulls with a

force of 25N to the left. Hannah pulls with

a force of 30N to the right. What is the net

force on the toy?

Nonrenewable energy resources do not include which of the following?

A ray of yellow sodium light enters water from air with an angle of incidence of 45°. What is the angle of refraction?

What weighs more a mole of feathers or bricks?

Can work be done on a system if there is no motion?

Calculate the speed of a proton having a kinetic energy of 0.995 * 10-19 J and a mass of 1.673 * 10-27 kg. Answer in units of m/s.

What is the difference between weight and mass?

An object has a mass of 8.00 kg. What is the gravitational force on the object by the earth?

Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive B. The sign of ΔG is zero C. The sign of ΔG is negative D.

In a recent hockey game, one player (m=100kg) was moving at a velocity of 8 m/s when he ran into another player (m=300kg) who was at rest (v=0m/s). After the collision, the two players were stuck together (moving with the same velocity).

In a laser, electrical energy is changed to light energy, and a small amount of the energy is wasted as heat. Describe the total amount of the heat in the system (using the conservation of energy).