<p>U8 ENERGY- WS2 NAME______Per._____</p><p>1. Mr. Dominic (on a good day) can bench press 30 kg. A. Draw a force diagram for the 30 kg barbell as he lifts it at constant speed. </p><p>B. As Mr. D lifts the barbell, does the force of gravity on the barbell change? ______</p><p>C. Draw bar charts showing the energy transfer for the barbell as he lifts it. Before lifting halfway up At its highest point Objects in system:</p><p>D. Construct a graph to the right showing the Force of gravity on the barbell (weight) vs. the height it travels (Mr D’s arms Fg (N) are 0.9 m long). (Assume Ediss is negligible.) 400</p><p>E. Shade in the area on your graph that represents the Gravitational Potential Energy the barbell gains as Mr. D 200 lifts it. Calculate this amount of Eg. Label this Energy on your graph. </p><p>F. Write an equation for how to calculate Eg, based on what you did in part E. 0.2m 0.4m 0.6m 0.8m h (m) Eg =</p><p>2. A 36 g pendulum is raised from point B to point A as shown. </p><p>A. Identify height = 0 on the scale and calculate the gravitational potential energy (Eg) at point A. </p><p>B. Draw quantitative bar charts to show the energy transfer from point A to rulings are 0.5 point B. cm apart</p><p>Objects in system:</p><p>A v = 0</p><p>B rulings are 0.5 cm apart 3. Benji uses 60 J of energy to lift a kitty cat 1.5m. What is the cat’s mass?</p><p>4. Jimmy (mass = 75 kg) gains 66.2 J of gravitational potential energy when he jumps 1.5 meters high on Pluto. What is the gravitational field strength on Pluto?</p><p>5. A 1500 kg car going 22 m/s stops in 4.5 seconds. A. Calculate its acceleration and the net force on the car. Draw a force diagram for the car while it is braking. </p><p>B. Draw qualitative bar charts showing the energy transfer from the time the car begins to brake until it stops. Objects in system:</p><p>C. The car’s brakes can stop it over a distance of 25.meters. Using the friction force you calculated in Ff (N) part A, construct a graph of the force of friction vs. 8000 the stopping distance. </p><p>D. Shade in the area that represents the energy that is dissipated during braking. 4000</p><p>E. Write an equation for how to calculate Edis, based on what you did in part D.</p><p>6m 12m 18m 24m distance F. Calculate the energy (Ediss) during braking. </p><p>G. To what object(s) is the energy dissipated during braking?</p><p>H. What similarities exist between this graph and the one in problem 1D ? </p><p>I. Based on these two graphs, how would you define energy? What units are equivalent to a Joule?</p><p>6. It took 76 joules of energy for Marquita to travel 8 meters before she stopped while playing on a “Slip ‘n Slide”. How big was the friction force that stopped Marquita? </p>