Belly- flop Bernie dives from atop a tall flagpole into a swimming pool below. His potential energy at the top is 8000 J (relative to the surface of the pool).  What is his kinetic energy when his potential energy reduces to 1000 J? express your answer to two significant figures and include the appropriate units.

Same set-up for the conservation of energy was performed. The 5-g marble covered a horizontal distance of 40 cm from the edge of the ramp (horizontal) from an elevation of 15 cm above the ground. At what height (in cm) relative to edge of the ramp was the marble released? Use g=9.8 m/s2. Round off your answer to two decimal places.

A roller coaster starts with a speed of 4.1 m/s at a point 51 m above the bottom of a dip. Neglecting friction, what wil be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip? Answer: m/s

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.

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?

Please atleast answer this question

Jacob is riding his bike down a tall hill. At the top of the hill, he has 2800J of potential energy. At the bottom of the hill, when he is going the fastest, his kinetic energy measures 2650J. Which statement below is true? (AKS 7a/DOK 2) 4. A. The total amount of energy at the bottom of the hill cannot equal the amount at the top, because some of the energy is destroyed. B. The total amount of energy at the bottom of the hill cannot equal the amount at the top, because some of the energy is gained. C. The total amount of energy at the bottom is equal to the amount at the top, but he gained some energy as he traveled due to a higher speed. D. The total amount of energy at the bottom is equal to the amount at the top, but some energy was converted into other forms due to friction.

Please use the information in the picture to answer the question: How fast must it have leapt from the water to reach a such a great height and speed. If you stand at the bow where you can reach up to a height of 3m above the water. You can only catch a fish if it is traveling under 8.5m/s when it reaches you. Will you be able to catch the fish? Find the speed of the fish at your location. Hint: use energy conservation.

The energy needed to increase the speed of a certain car from 22 m/s to 54 m/s is 2900 kJ. A) What is the mass of the car? B) At what speed is the cars kinetic energy equal to 1500 kJ? C) The car is driven up pikes Peak, an elevation gain of 5500 feet from the base. What is the change of potential energy of the car? give the answer in Joules. 

A brick lies perilously close to the edge of the flat roof of a building. The roof edge is 50 ft above street level, and the brick has 260.0 J of potential energy with respect to street level. Someone edges the brick off the roof, and it begins to fall. What is the brick’s kinetic energy when it is 35 ft above street level? What is the brick’s kinetic energy the instant before it hits the street surface?