Sally pulls on the rope shown below with a force of F. The rope forms an angle of 50° with the horizon. The horizontal surface has a coefficient of friction of 0.1. Sally accelerates at 0.4 m/s?. The mass of the box is 5 kg. A.Determine the magnitude of the force F. B.Determine how much work Sally does in moving the box 15 meters to the right. C.Determine how much work friction does as the box is moved 15 meters to the right.

A bicycler is moving at 8m/s when they reach the top of a 20m high hill. They coast 15m to the bottom of the hill. They are moving 15m/s when they reach the bottom of the hill. The combined mass of the bicycler and the bicycle is 95kg. a. Calculate the work done by friction on the bicycler. b.Calculate the magnitude of the force of friction acting on the bicycle.

Identify each situation as: WORK IS DONE or WORK IS NOT DONE          a.A teacher applies force to a wall and becomes exhausted.          b.A book falls off the table to the ground.          c.A rocket accelerates through space

A baseball hits the catcher’s glove with a horizontal velocity of 55m/s. The mass of the baseball is 0.15kg. The displacement of the ball due to the deformation of the catcher’s glove and the movement of the catcher’s hand is 23cm from the instant the ball makes contact with the glove until it stops. a. How much kinetic energy does the baseball have just before it strikes the glove? b. How much work does the catcher have to do to the ball during the catch and is it positive or negative? c. What is the average impact force exerted by the glove on the baseball? Answer parts a-c. Include units and direction.

A 500 kg cart rests atop a hill 30.0 m high on a roller coaster. Its gravitational potential energy is measured relative to the bottom of the hill. The cart then rolls down the hill. Which of these best describes what is happening in this situation?   a. the total mechanical energy of the cart is decreasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is increasing   b. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is increasing   c. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is increasing, and the gravitational potential energy of the cart is decreasing   d. the total mechanical energy of the cart is increasing, the kinetic energy of the cart is decreasing, and the gravitational potential energy of the cart is increasing   e. the total mechanical energy of…

Which of the statements below is true when you catch a baseball that comes at you horizontally?   a. The work that you do is positive.     b. The work that you do is negative.   c. Work is not a vector and cannot be referred to as positive or negative.       d. Work is a scalar product expressed in terms of magnitudes, so it is never negative.     e. Work is expressed in terms of kinetic energy, which must be positive.

You lift a box off the ground and then hold it at a height above your waist. Which does not describe the work or energy in this process? A. You did positive work on the box. B. Gravity did negative work on the box C. The box's gravitational potential energy increased. D. The box's kinetic energy remained constant throughout the process.

Which of the following statements are TRUE? A. Energy is a vector physical quantity. B. Energy is always required to do work. C. Totol mechanical energy can never be zero. D. When law of conservation of mechanical energy is invoked, there can never be a waste energy in an ideal system. E. When law of conservation of mechanical energy is invoked, there can never be a waste energy in a real-world system. F. Kinetic energy can be negative. G. Potential energy can be negative. H. Work is equivalent to the negative change in kinetic energy. I. Work is equivalent to the negative change in potential energy. J. In a conservative system where only gravitational force acts, the total mechanical energy is constant at every point of the motion. K. In a non-conservative system where certain external forces may act, the total mechanical energy is not constant at every point of the motion. L The entire universe may be considered as a closed system where the total energy is constant. chnices O B. D.…

A body moves with increasing speed.  Which of the following statements is true? A. The net work done on the body is positive, and the kinetic energy is increasing. B. The net work done on the body is positive, and the kinetic energy is decreasing. C. The net work done on the body is zero, and the kinetic energy is decreasing. D. The net work done on the body is negative, and the kinetic energy is increasing. E. The net work done on the body is negative, and the kinetic energy is decreasing.

A 100 kg block is pulled at a constant speed of 5 m/s across a horizontal force by an applied force of 122 N directed 37^o above the horizontal. The rate at which the force does work on the block is ____. a. 810 Watts b. 490 Watts c. 530 Watts d. 704 Watt