Which statement explains how it is possible to carry books to school without changing the kinetic or potential energy of the books or doing any work? By moving the book without acceleration and increasing the height of the book slowly. By moving the book with acceleration and keeping the height of the book constant By moving the book with acceleration and changing the height of the book D By moving the book without acceleration and keeping the height of the book constant By moving the book without acceleration and changing the height of the book

A block of mass 10 kg moves from position A to position B shown in the figure. The speed of the block is 10 m/s at A and 6.0 m/s at B. The work done by friction on the block as it moves from A to B is most nearly. * 4 m 2 m 3m -280 J -220 J -200 J -120 J -96 J

A 69.0-kg athlete leaps straight up into the air from a trampoline with an initial speed of 8.9 m/s. The goal of this problem is to find the maximum height she attains and her speed at half the maximum height a) what is the gravitational potential energy associated with the athlete

2

*Chapter 8, Problem 55 In the figure, a block of mass m = 3.6 kg slides head on into a spring of spring constant k = 360 N/m. When the block stops, it has compressed the spring by 11 cm. The coefficient of kinetic friction between block and floor is 0.39. Wwhile the block is in contact with the spring and being brought to rest, what are (a) the work done by the spring force and (b) the increase in thermal energy of the block-floor system? (c) What is the block's speed just as the block reaches the spring? (a) Number 1 Units (b) Number 72 Units (c) Number 1+3 Units

A child throws a stone upwards. While the stone is moving upwards the gravitational force does positive work on it and the gravitational potential energy increases. the gravitational force does positive work on it and the gravitational potential energy decreases. the gravitational force does negative work on it and the gravitational potential energy increases. O the gravitational force does negative work on it and the gravitational potential energy decreases.

.

i object 'A' with a mass of 4 kg is lifted vertically 4 m from the ground level; another object 'B' with a mass of 2 kg is lifted 8 mup. Which of the following statements is true? Object I has greater potential energy since it is heavier I. I. Object II has greater potential energy since it is lifted to a higher position II. Two objects have the same potential energy

1) A constant horizontal force of F = 200.0 N pushes a crate of mass m = 25.0 kg, initially at rest, along a rough horizontal surface. The crate travels a total distance of 8.00 m, and the coefficient of kinetic friction between the crate and the surface is 0.250. a) What is the work done on the crate by the force F? b) How much does friction increase the internal energy of the crate-surface system ?

A boy pushes his wagon at constant speed along a level sidewalk. The graph (right) below represents the relationship between the horizontal force exerted by the boy and the distance the wagon moves. What is the total work done by the boy in pushing the wagon 6.0 meters? * Force vs. Distance 40.0 30.0 20.0 + to 10.0 0.0 0.01.0 2.0 3.0 4.0 5.0 6.0 Distance (m) 5.0 J 7.5 J 120 J 180 J Force (N)