A0.20 kg ball was thrown vertically upward from a 20-m high building with a speed of 10 m/s. On its way down it misses the edge of the building and continued to move to the ground. Assume the ball was thre wn 1 meter above the roof of the building. Using the roof of the building as the reference for zero potential, what is the potential energy of the ball when it reaches the ground? (use g 9.8 m/s)

1. Boxing gloves are padded to lessen the force of a blow. The glove and face compress 7.5000 cm during a blow in which the 7.0000-kg arm and glove are brought to rest from an initial speed of 10.0000 m/s. ▬▬ - Think & Prepare 1. Make note of what's given and what's unknown. Relate known quantities to symbols. 2. Draw a labeled sketch if possible. 3. Identify the physics principle and approach. Write down relevant equations symbolically. Simplify if possible. 4. Insert numerical quantities to solve for unknowns. 5. Does the answer make sense? % (a) Calculate the change in kinetic energy of the glove and arm. AKE = (b) Where does this energy go? O Search 5 O into doing work against the force exerted by the face against the glove O into doing work against gravity O into the potential energy of the face O into the potential energy of the glove and arm T 4- 6 Y 17 + & J 7 90 8 * 8 U I 이 144 ( 9 110 DII O E DDI I P 2 { 4 ( ← backs

A block of mass 3 kg compresses spring 1 with a force constant, k1=7000 N/m, by 6 cm. It is released and slides for a total of 50 cm on a surface with μk=0.2, at which point it compresses another spring 2, k2=1000 N/m, and momentarily comes to rest. Remember that Us is the potential energy of the spring. Find the following values:What is the Initial spring potential energy of spring 1? How much energy is dissipated by heat? This is the amount of work done by friction × -1. How much Potential Energy does spring 2 have when the block has compressed spring 2 and is momentarily stopped? By how much does spring 2 compress?

please quickly, solve question

A child of mass m = 16 kg slides down a slide of height h = 2.7 m without friction. Let gravitational potential energy be zero at ground level. a)Write an expression for the child's total mechanical energy, E, at the top of the slide, in terms of the variables in the problem and the acceleration due to gravity g.  b)Calculate the change in the child's potential energy, ΔU in joules, from the top to the bottom of the slide at ground level (i.e. ΔU = Uground - Utop).  c)What is the child's final speed, vf in m/s?

In the figure, a frictionless roller coaster car of mass m - 992 kg tops the first hill with speed vo- 11.9 m/s at heighth-47.0 m. How much work does the gravitational force do on the car from that point to (a) point A, (b) point B, and (c) point C? If the gravitational potential energy of the car-Earth system is taken to be zero at C, what is its value when the car is at (d) Band (e) A? First

A box slides down a ramp and work is done on the box by the forces of gravity and friction. Can the work of each of these forces be expressed in terms of the change in a potential-energy function? For each force explain why or why not.

Calculate the potential energy of a 430g book being help at 1.9m off the ground. Report your answer in J.

A ball toy of mass 19.1 g is thrown straight up with an initial speed of 4 m/s. Neglect air resistance. If the gravitational potential energy is taken to be zero at the maximum height the toy reaches, what would the gravitational potential energy be in J when it leaves the hand? Give your answer to 2 decimal places.

15. A particle is subject to a force F, that varies with posi- W tion as shown in Figure P7.15. Find the work done by the force on the particle as it moves (a) from x = 0 to 5.00 m, (b) from x = 5.00 m to x = 10.0 m, and (c) from x= 10.0 m to x = 15.0 m. (d) What is the total work done by the force over the distance x = 0 to x = 15.0 m? x= F, (N) 3 2 1 0 x (m) 2 4 6 8 10 12 14 16 Figure P7.15 Problems 15 and 34.