Two identical stones are thrown from the top of a tall building. Stone 1 is thrown vertically downward with an initial speed of v, and stone 2 is thrown vertically upward with the same initial speed. Neglecting air resistance, how do their speeds compare on hitting the ground?

Consider a cannon-ball of mass 8 kg fired vertically up from the ground with an initial speed of 120 m/s. We ignore the effects of air resistance. (a) Consider the downward trip. Find the work done by gravity when the cannon-ball drops from its highest point to halfway between the ground and the highest point. Hence, find the kinetic energy of the cannon-ball when it drops to the halfway point. (b) Mark a list that gives the kinetic energy, potential energy and the total mechanical energy at four points during the trip: when the cannon-ball (i) just leaves the cannon, (ii) reaches its highest point, (iii) is half-way in the downward trip, and (iv) is going to hit the ground.

A pebble is released from rest at a certain height and falls freely, reaching a speed of 4 m/s at the floor.Next, the pebble is thrown down with an initial speed of 3 m/s from the same height. What is its speed at thefloor? (a) 4 m/s (b) 5 m/s (c) 6 m/s (d) 7 m/s (e) 8 m/s

A 30.0-kg child starting from rest slides down a water slide with a vertical height of 10.0 m. What is the child’s speed (a) halfway down the slide’s vertical distance and (b) three-fourths of the way down? (Neglect friction.)

How much work is done stretching Achilles tendon from rest by 1 cm? Tendon stiffness is 287 500 N/m.

A 1943 kg rollercoaster is released from an initial height of 52 m above the ground and will eventually reach Point Awhich is 16 m above the ground, and Point Bwhich is 35 m above the ground. How fast is the car moving at Point A? Note: There is no friction on this track?

A 54 kg student carrying an 11 kg backpack climbs up 76 steps (each step is 18 cm high) to the 4th floor then walks horizontally 8 meters from the top of the steps to physics class. how much gravitational potential energy do she and the backpack gain altogether ?

In an amusement park, a roller coaster cart begins at 70 meters above the ground and glides down a frictionless track. Determine the speed of the cart at 20 meters above the ground.

how fast would a 30 kg child be moving from top to bottom on a zipline starting at a height of 43.6 meters? (Ignore effects due to friction.)

At the local playground, a child on a swing has a speed of 2.22 m/s when the swing is at its lowest point.To what maximum vertical height does the child rise, assuming he sits still and "coasts"? Ignoring air resistance.