ohn, of mass 82.4 kg can do work for about 2.0 minutes at the rate of 1.0 hp. How long will it take him to climb three flights of stairs, a vertical height of 12.0 m? 1 hp= 746 watts a) 8.2 s b) 130 s c) 13 s d) 9.1 s

Questions D and E

A 6.50 kg box slides 4) from the top of a ramp to the bottom at a constant speed, as shown in the diagram. constant v= 1.50 m/s h= 1.85 m 0= 28.2° a) How much work is done on the box by the frictional force? b) How much work is done on the box by gravity? c) How much work is done on the box by the normal force? d) What is the coefficient of kinetic friction between the box and the ramp?

question 6

7. A student in a lab exerts a 25 N force to pull a block a distance of 48 cm. If a total of 11 J of work is done, the angle between the force and the displacement is a. 89° b. 66° d. 24° e. none of the above c. 61° 8. A 102-g sparrow flying at 12.3 m/s wishes to have equal kinetic and gravitational potential energies. The height that will accomplish this is a. 0.315 m b. 0.628 m d. 1.13 m e. 7.72 m c. 0.787 m 9. Earth's mass is 5.98 x 1024 kg. Calculate the value of g at a point 4.8 x 105 km from the centre of Earth. a. 9.8 × 102 N/kg b. 8.3 x 10' N/kg C. 1.7 × 103 N/kg d. 1.7 x 10³ N/kg e. 9.8 × 105 N/kg 10. A piece of paper becomes electrically charged when a charged rod of plastic is placed close to it. This is referred to as a. charging by a conductor b. charging by induction c. charging by an insulator A P d. charging by contact e. charging by electricity 20 cm Ꭰ T 20 cm 11. Four charged spheres, A, D, P, and T are arranged as shown below. Sphere A has a charge of +4.5 × 10*C,…

A 2.0 kg rock is released from rest at a height 0f 20.0 m. Ignore air resistance and determine the kinetic energy, gravitational potential energy, and total mechanical energy at each of the following heights: 20.0, 15.0, 10.0, 5.0 and 0m

What is the magnitude of the angular momentum of the 2.40 kgkg , 4.20-cm-diameter rotating disk in the figure (Figure 1)?

3. A 60 kg boy does 60 push-ups in 40 s. With each push-up he must lift an average of 70 % of his mass a height of 40 cm off the floor. Calculate the following: a) the work the boy does for each push-up, assuming he does work only when he pushes up b) the total work done in 40 s c) the power for this period

Find the work done in joules by gravity as an object of the mass m 5 kg is raised up at constant speed from a height h;=26 m to a height h2=69 m. Consider g = 10 m/s2 A. None B. -2150 D. -6450 E. -4300 O < O a OUO DOE

150.0 J of work is done while lifting a 200.0 N box 0.75 meters up over your head towards a shelf. Given this information, how much P.E. does the box after it was raised? A) 0 J B) 150 J C) 266.67 J D) 1102.5 J E) don't be silly, it's none of these!