Question 20 (4 points) A roller coaster car has a mass of 290 kg. Starting from rest, the car acquires 3.13 x 10 Joules of kinetic energy as it descends to the bottom of a hill in 5.3 seconds. a. Calculate the height of the hill. [Neglect friction.] b. Calculate the speed of the roller coaster car at the bottom of the hill. C. Calculate the magnitude of the average acceleration of the roller coaster car as it descends to the bottom of the hill. [Click on in your answer box to use more math tools] Paragraph v B IUV Ev Ev + . . . Lato (Recom... 19px .. EQ > C Question 21 (2 points) A pop-up toy has a mass of 0.020 kg and a spring constant of 150 N/m. A force is applied to the toy to compress the spring 0.050 meter (see the following Figure). Force (o (o Suction cup Spring that compresses Base a. Calculate the potential energy stored in the compressed spring. b. The toy is activated and all the compressed spring's potential energy is converted to gravitational potential energy. Calculate the maximum vertical height to which the toy is propelled.Question 11 (1 point) A car of mass 1200 kg travels along a horizontal road at a speed of 10 m s"]. At the time it begins to accelerate at 0.2 m s2, the total resistive force acting on the car is 160 N. What is the total output power developed by the car as it begins the acceleration? O 0.80 KW O 1.6 KW O 2.4 KW O 4.0 KW Question 12 (1 point) A ball with a mass of 125 g is on top of a bookcase that is 2.95 m tall. The ball rolls off the bookcase where it bounces on the floor and lands on the top of a table. If the tabletop is 1.20 m above the floor, what is the magnitude of the change in gravitational potential energy of the ball after it lands on the table? 3.62J 1.47 J ( 4.42 J (2.15 JQuestion 13 (1 point) How much work must be done to compress a spring a distance of 36.0 cm from its equilibrium position if the spring has an elastic constant of 3.25 x 103 N/m? 1.17 x 103 J 5.85 x 102 J 4.21 x 102 J 2.11 x 102 J Question 14 (1 point) A spring has an elastic constant of 8.75 x 105 N/m. What is the magnitude of the force required to stretch this spring a distance of 28.6 cm from its equilibrium position? 3.06 x 102 N 7.16 x 102 N O 3.06 x 103 N Question 15 (1 point) A force of 56.0 N does work over a displacement of 24.5 m. If the angle between the force and the displacement is 35.0, what is the work done by this force? 1.37 x 103 J 1.12 x 103 J 9.61 x 102 J ( 7.87 x 102 JQuestion 16 (1 point) A roller coaster trolley with a mass of 2.30 x 10" kg begins to coast up a hill at a point 4.25 m above the ground. The trolley has an initial speed of 16.5 m/s. At the top of the hill that is 19.6 m above the ground, the trolley has a speed of 1.12 m/s. What is the work done on the trolley as it coasts up the hill? 6.58 x 105 J 6.00 x 104 J 3.47 x 104 ] 3.32 x 104 J Question 17 (1 point) The pendulum has a length of 1.20 m and a bob of mass 2.50 kg. The pendulum bob is pulled sideways until it is 30.8 cm above its rest position. What will be its kinetic energy when it passes through the lowest point of its motion? O 2.46 J ( 5.92J O 6.04 J ( 7.55 JQuestion 18 (1 point) A winch motor generates a power of 55.0 KW when it is used to lift a 6.50 x 102 kg bucket of concrete to a height of 75.0 m. If the time required to do this is 25.0 s, what is the efficiency of this system? 26.5% 27.8% 29.6% C 34.8% Question 19 (1 point) In terms of kg, m, and s, which of the following is the unit for power? kom kgm O kgm O kom $ 3