The sum of the kinetic and potential energy in a system is known as the system's _____________________ energy.

• mechanical

• chemical

• thermal

• combined

A spring with spring constant 4 N/m is compressed by 0.25 m. How much energy is stored in the spring? NO WORK REQUIRED

• 1 J

• 0.25 J

• 0.125 J

• 16 J

Friction always does...

• Zero work

• Positive work

• Negative work

• Friction is not considered a force

A pendulum is released from rest at point A. Below are 4 energy diagrams. The red bar stands for kinetic energy, the blue stands for potential and the green is the total energy. Which bar diagram describes the pendulum-Earth system at point D?

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A pendulum is released from rest at point A. Below are 4 energy diagrams. The red bar stands for kinetic energy, the blue stands for potential and the green is the total energy. Which bar diagram describes the pendulum-Earth system at point F?

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A sled is pulled along a frictionless surface by a 240 N force applied at a 60-degree angle. The sled moves 7 m. Calculate the total work done on the sled. SHOW YOUR WORK.

• 840 J

• -1600 J

• 1680 J

• 28 J

A roller-coaster starts from rest at point 1. Assuming there is no friction, calculate. the speed of the roller-coaster at point 4. SHOW YOUR WORK.

The work-energy theorem says that

• The work done by a single force is equal to the change in the kinetic energy of the object

• The TOTAL or NET work done on an object is equal to the change in kinetic energy of the object

• The TOTAL or NET work done on an object is equal to the change in the gravitational potential energy of the object

• The work done by a single force is equal to the change in the object's speed

A block of mass 2 kg has a speed of 7 m/s. It comes into contact with a spring, the spring compresses a distance of 0.3 m, and the block comes to rest. Use the conservation of energy to find the spring contsant. SHOW YOUR WORK.

The formula for elastic potential energy is

• $U_S=mgh$

• $U_S=\frac{1}{2}kx^2$

• $U_S=\frac{1}{2}mv^2$

• $U_S=-\nabla E$