Consider the four possible paths of a body moving through gravity as diagrammed below. Which of the following statements is true? Projectile A a. The work done by gravity is greatest for path B. b. The work done by gravity is greatest for path C. C. The work done by gravity is greatest for path D.

Boxing gloves are padded to lessen the force of a blow. a. Calculate the force (in N) exerted by a boxing glove on an opponent's face, if the glove and face compress 6.50 cm during a blow in which the 6.00 kg arm and glove are brought to rest from an initial speed of 10.0 m/s b. Calculate the force (in N) exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (Assume the total mass of the arm remains 6.00 kg.) c. Discuss the magnitude of the force with glove on. Does it seem high enough to cause damage even though it is lower than the force with no glove?

Activity 2 – Kinetic Energy Solve the following problems with complete solutions. 1. Calculate the speed of an 8.0 × 10* kg airliner with a kinetic energy of 1.1 × 10° J. 2. What is the speed of a 0.145 kg baseball if its kinetic energy is 109 J? 3. Two bullets have masses of 3.0 g and 6.0 g, respectively. Both are fired with a speed of 40.0 m/s. Which bullet has more kinetic energy? What is the ratio of their kinetic energies?

Identify each situation as: WORK IS DONE or WORK IS NOT DONE          a.A teacher applies force to a wall and becomes exhausted.          b.A book falls off the table to the ground.          c.A rocket accelerates through space

A 500 kg cart rests atop a hill 30.0 m high on a roller coaster. Its gravitational potential energy is measured relative to the bottom of the hill. The cart then rolls down the hill. Which of these best describes what is happening in this situation?   a. the total mechanical energy of the cart is decreasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is increasing   b. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is increasing   c. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is decreasing   d. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is decreasing, and the gravitational potential energy of the cart is increasing   e. the total mechanical energy of…

There are 2 cars. Assuming the first car has a mass of 1000 Kg, which has greater kinetic energy? a. The first car traveling at 30 m/s b. a second car of half the mass traveling at 60 m/s. c. both have the same kinetic energy d. need more information

A 65 kg person rides a 20 kg bicycle at a speed of 11 m/s. The cyclist runs into a parked car and comes to a fast stop. The bike collapses 0.95 m during the crash.  a) Determine the kinetic energy of the cyclist/bike before the crash.  b) Find the average force exerted on the cyclist/bike by the parked car.

Three identical balls are thrown from the edge of a cliff, each with the same initial speed. Ball 1 is thrown directly upward. Ball 2 is thrown directly downward. Ball 3 is thrown horizontally. Which of the following statements correctly characterizes the relative kinetic energies (K) of the three balls just before hitting the ground. A. K1 = K2 K3 O C. K1 = K2 = K3 D. K1 K2 > K3

A car is accelerated from velocity v1 to v2 in the time period of t . The mass of the car is m. The inclined angle of the hill is α. The distance travelled along the hill is L. The vertical distance travelled is H. Select the equation used to calculate the potential energy increase of the car ΔPE______     A.     B. ΔPE=mgH   C. ΔPE=mgL   D.

? V m In the above image we see a 3.43 kg box that is moving to the right at 19.5 m/s. The box hits into a rough patch that applies a frictional force of 277 Newtons until the box comes to a stop. time K.E. E.P.E. Joules G.P.E. M.E Initial Joules Joules Joules Final Joules Joules Joules Joules How much work was done on the box by friction? Joules How far would the box travel before coming to a stop? meters