20kg 2.5 m 7. Slim Jim's dog "Bim" is on a ledge 2.5m above a spring board. If he compresses it 0.45m, what is the spring constant for the board? A. Ebefore= Work? = B. Conservation of Energy equation: C. Solve. Eafter= T 8. Slim Jim finds a giant spring that has a 350 N/m spring constant. Jim figures out how to compress it 1.5 m. If Jim and his spring propelled cart's mass is 85kg, how fast is he going after he releases the lever? A. Ebefore= Work? = B. Conservation of Energy equation: C. Solve. Eafter = 60 kg 5 m/s 350N/m 85kg 9. Slim Jim runs 5m/s at full speed. If he grabs a rope at the ground, how high off the ground will he swing? A. Ebefore= Work? = B. Conservation of Energy equation: C. Solve. Eafter = 10. A 4 kg object is moving 15m/s. If it stops due to friction in 3.5m, what is the magnitude of the force of friction? (Calculate Fk.) A. Ebefore= Work? = B. Conservation of Energy equation: Eafter = C. Solve. D. How much energy did it lose? Before After 3.5m 4 kg 15 m/s 2 sec 4 kg 0 m/s E. Since this energy was lost in 2 seconds, how much power did friction dissipate (use up)?