Calculate the work done in lifting a 520-NN barbell 1.8 mm above the floor. Express your answer to two significant figures and include the appropriate units. What is the gain of potential energy of the barbell when it is lifted to this height? Express your answer to two significant figures and include the appropriate units.

A puck with a mass of 159.0 g is sliding with an initial velocity 31.0 m/s.  The puck enters a section of rough ice and slows to a speed of 15.1 m/s.  What is the magnitude of the work done on the puck by the rough ice?  Express your answer in Joules to 1 decimal place.

A force of 17 Ib is required to hold a spring stretched 3 in. beyond its natural length. How much work W is done in stretching it from its natural length to 9 in. beyond its natural length?

A horizontal spring is stretched 10 cm and then released from rest. Will the spring ever stretch a distance greater than 10 cm? Explain why or why not using the idea of energy conservation.

A 61.5-kg hiker starts at an elevation of 1200 m and climbs to the top of a peak 2750 m high. Part A What is the hiker's change in potential energy? Express your answer to three significant figures and include the appropriate units. ΔΡΕς = Submit Part B W min = Submit Part C What is the minimum work required of the hiker? Express your answer to three significant figures and include the appropriate units. O Yes O No Value Submit μA Request Answer ī μÅ Value Request Answer Units Can the actual work done be greater than this? Request Answer Units ? ?

How much work is done when you push a crate horizontally with 120 NN across a 11-mm factory floor? Express your answer to two significant figures and include the appropriate units. WW = 1300 JJ If the force of friction on the crate is a steady 70 NN, find the KE gained by the crate. Express your answer to two significant figures and include the appropriate units.

In this problem use g = 10m/s^2. The weight of the object is  W = mg. 1)Find the work done on the object by the force F.  2) Find the magnitude of the normal force between the object and the floor. Answer in Newton. 3)Find the work done on the object by friction.   4)Find the final kinetic energy of the object. Answer in Joule.

6. Please answer

In the figure below, the force component F cos e reaches a maximum at s = 0.306 m. Find the percentage of the total work that is done when the bowstring is moved in the following ways. 2.78 x 102 m 9.00 N 180.0 N F cose 108 N 0.500 m (a) from s = 0 to 0.306 m X % Enter a number. (b) from s = 0.306 to 0.500 m %

A 70.5-kg hiker starts at an elevation of 1260 m and climbs to the top of a peak 2800 m high. a.)What is the hiker's change in potential energy? Express your answer to three significant figures and include the appropriate units. b.)What is the minimum work required of the hiker? Express your answer to three significant figures and include the appropriate units.