A rock falls from a vertical cliff that is 4.0 m tall and experiences no significant air resistance as it falls. At what speed will its gravitational potential energy (relative to the base of the cliff) be equal to its kinetic energy?     3.1 m/s     4.4 m/s     13 m/s     8.9 m/s     6.3 m/s

A box of unknown mass is sliding with an initial speed v₁ = 4.30 m/s across a horizontal frictionless warehouse floor when it encounters a rough section of flooring d = 2.80 m long. The coefficient of kinetic friction between the rough section of flooring and the box is 0.100. Using energy considerations, determine the final speed of the box (in m/s) after sliding across the rough section of flooring. m/s

An object with an initial potential energy of 40 J is dropped from rest. After a while, its potential energy is 10 J, and its kinetic energy is 5 J. Construct a possible scenario that might explain this situation.

A 7.44-kg particle is subject to a net force that varies with position as shown in the figure. The particle starts from rest at x = 0. Fx (N) 3 2 2 4 6 8 10 12 14 16 What is its speed at the following positions? (a) x = 5.00 m 154.32 X Can you determine the kinetic energy of the particle at x = 5.00 m from the given graph? m/s (b) x = 10.0 m 154.33 x (m) X You appear to have added your result from part (a) to a speed calculated from the work done between 5 and 10 m. This doesn't work; you must calculate the work done over the entire 10 m distance. m/s (c) x = 15.0 m 151.31 X The force is positive throughout the entire interval. Does it make sense that the speed would decrease m/s

A 7.44-kg particle is subject to a net force that varies with position as shown in the figure. The particle starts from rest at x = 0. Fx (N) 3 2 2 4 6 8 10 12 14 16 What is its speed at the following positions? (a) x = 5.00 m x (m) X Can you determine the kinetic energy of the particle at x = 5.00 m from the given graph? m/s (c) x = 15.0 m (b) x = 10.0 m 1 X How would you calculate the total work done on the particle between 0 and 10 m? m/s X The force is positive throughout the entire interval. Does it make sense that the speed would decrease m/s

A 3.5-kg object falls vertically downward in a viscous medium at a constant speed of 1.5 m/s. How much work is done by the force the viscous medium exerts on the object as it falls 50 cm?   Question 11 options:   +2.0 J   -8.5 J   +17 J   −17.0 J   −32 J

A 2.5 kg bowling ball is tied to a 1m long string attached to the ceiling. The ceiling is 5 m above the floor. What is its change in potential energy relative to the floor? 31.3 J O 122.5 J 98.0 J O 24.5 J

A 76.0-kg hiker is descending a mountain that has a peak altitude of 2350 m above sea level. The hiker has a device that measures her potential energy, and when she is at the peak of the mountain she decides to "zero" it (that is, she set's the zero point of potential energy to be the mountaintop). What does her potential energy device read sometime later on her descent when she is 1960 m above sea level?

A 0.27-kg stone is held 1.2 m above the top edge of a water well and then dropped into it. The well has a depth of 5.6 m.   (a) Taking y = 0 at the top edge of the well, what is the gravitational potential energy of the stone–Earth system before the stone is released? (b) Taking y = 0 at the top edge of the well, what is the gravitational potential energy of the stone–Earth system when it reaches the bottom of the well? (c) What is the change in gravitational potential energy of the system from release to reaching the bottom of the well?

During a rockslide, a 390 kg rock slides from rest down a hillside that is 460 m long and 300 m high. The coefficient of kinetic friction between the rock and the hill surface is 0.24. If the gravitational potential energy U of the rock-Earth system is set to zero at the bottom of the hill, what is the value of U just before the slide?1.15×106 J How much mechanical energy is dissipated by frictional forces during the slide? What is its speed then? What is the kinetic energy of the rock as it reaches the bottom of the hill?