A child has two red wagons, with the rear one tied to the front by a (non-stretching) rope. If the child pushes on the rear wagon, what happens to the kinetic energy of each of the wagons, and the two-wagon system?

4) An archer draws his compound bow and shoots an arrow. The 25 g arrow leaves the bow with a velocity of 95 m/s. The power stroke of the bow is 57 cm; that is, the bowstring exerts force on the arrow through a displacement of 57 cm. The peak draw weight of the bow is 312 N. (This is the maximum force that the archer has to exert on the bowstring.) a. How much kinetic energy does the arrow have after release? b. If shot straight up, how high will the arrow go?

A 10.0-kg bob is attached to a rod whose length is 10.0 m. The right end of the rod is fixed, and the bob is released from rest. a) Determine the speed of the bob when it is below the pivot point (vertical angle is zero). b) Determine the tension in the rod when the bob is below the pivot point. hint: to determine the speed of the bob when it is below the pivot point, you will need to use Calculus.

At a circus a performer weighing 90kg is shot from a cannon vertically into the air at 45 m/s. To avoid killing the performer a bar must be hung so that they can grab it at the highest point of their launch. Where should the bar be placed? (Solve using conservation of energy)

Is it possible for a friction force to increase the total mechanical energy of a system? If so, give examples.

Kay is a 50kg pole vaulter with a standing center of mass of 1.0m. During the approach to her first vault she is able to run at a velocity 9.0m/s just before putting the pole to the ground but was unsuccessful at clearing the height of 5.5m. How much kinetic energy does Kay have just before putting the pole to the ground?   How much kinetic energy must Kay have to be able to achieve her goal height of 5.5m?   How fast must Kay run to be able to achieve her goal height?

(b) The following diagram shows a football rolling from A to G. Which letter shows the ball when it has the (1) Maximum kinetic energy and (ii) Maximum potential energy? Answer : The maximum potential energy at and maximum kinetic energy at

A 75kg bicyclist (including the bicycle), initially at rest pedals up a hill. She reaches a speed of 4m/s despite experiencing a 15N drag during her ride. The distance and height of the hill are shown. Neglect any friction impeding her motion and the rotational energy of the wheels. List the energy types at the initial and final time and whether work and loss (due to non-conservative forces) occur as well as the corresponding amounts of energy. initial: work? loss? final: none work loss GPE & KE 1111 0 11325 What is the average thrust she must generate? 153 unit

Sterling Archer has given up Lacrosse and taken up pole vaulting. At the end of his approach run during a pole-vault, he has a horizontal velocity of 8 m/s and his center of gravity is 1.0 m high.  If Archer has a mass of 50 kg, estimate how high he should be able to vault if his kinetic and potential energies are all converted to potential energy.