The net work done on an object may be determined by a combination of kinematics and dynamics or by the work-kinetic energy theorem. In this problem, we will first use kinematics and dynamics to determine the net work done on an object [parts (a), (b), and (c)], then we will use the work-kinetic energy theorem [part (d) and (e)] to again determine the net work done on the object. A bullet with a mass of 14.5 g is accelerated along the length of a 73.5 cm long rifle barrel from rest to a speed of 825 m/s. Determine the following. (a) the magnitude of the acceleration of the bullet as it travels along the rifle barrel (Assume the acceleration of the bullet is constant.)  km/s2 (b) the magnitude of the net force acting on the bullet as it travels along the rifle barrel  kN (c) net work of the bullet done as it travels along the rifle barrel  kJ

A force F→ is applied to a 2.0 kg, radio-controlled model car parallel to the x-axis as it moves along a straight track. Calculate the work done by the force F→ when the car moves from x = 0 to x = 3.0 m. Calculate the work done by the force F→ when the car moves from x = 4.0 m to x = 7.0 m.

(a) A block with a mass m is pulled along a horizontal surface for a distance x by a constant force F at an angle e with respect to the horizontal. The coefficient of kinetic friction between block and table is u. Is the force exerted by friction equal to u, mg? If not, what is the force exerted by friction? (Assume 0 is measured above the horizontal.) This answer has not been graded yet. (b) How much work is done by the friction force and by F? (Don't forget the signs. Use the following as necessary: F for the magnitude of F, g, m, x, 0 and u,) WE = (c) Identify all the forces that do no work on the block. (Select all that apply.) O friction f OF Cos(e) OF sin(0) O mE (d) Let m = 2.00 kg, x = 4.50 m, 0 = 3.7°, F = 14.5 N, and u, = 0.400, and find the answers to parts (a) and (b). (Include appropriate signs.) We = W =

(1) Suppose you lift a stone that has a mass of 5.1 kilograms off the floor onto a shelf that is 2.5 meters high. How much work have you done? 124.95 Joules (2) Suppose you lift a laptop that weighs 5.3 pounds off the floor onto a shelf that is 2 feet high. How much work have you done? 347.68 x foot-pounds (3) The force on a particle is described by 6x work done in moving the particle from the origin to x = 9. - 2 pounds at a point r feet along the r-axis. Find the 9823.5 Vo foot-pounds

A 60 kg box has an initial velocity of 12 m/s up a 60-degree inclined plane at an initial height of 0 meters. The coefficient of friction between the box and the ground is 0.2. [a] Calculate the box’s maximum height up the inclined plane. [b] Calculate the work done by friction. [c] If you increased the angle of the inclined plane, explain how that would affect the work done by friction.

A mountain climber is about to haul up a 90-m length of hanging rope. How much work will it take if the rope weighs 0.65 N/m? Set up the integral that gives the work done. (Type an exact answer, using radicals as needed.)

A 0.42 kg particle has a speed of 5.0 m/s at point A and kinetic energy of 7.5 J at point B. (a) What is its kinetic energy at A? (b) What is its speed at point B? lea ng m/s (c) What is the total work done on the particle as it moves from A to B? Need Help? Read It ds.

You stand at the top of a cliff and lower a first aid kit (attached to a rope) down the cliff to an injured hiker at a constant speed. What can you say about the work done by the rope and the work done by gravity on the kit as it is lowered? O The work done by the rope is positive and the work done by gravity is positive. The work done by the rope is negative and the work done by gravity is negative. O The work done by the rope is positive and the work done by gravity is negative. O The work done by the rope is zero and the work done by gravity is zero. O The work done by the rope is negative and the work done by gravity is positive.

(a) A force F= (2x1 + 4yĵ), where F is in newtons and x and y are in meters, acts on an object as the object moves in the /F. F. dr done by the force on the object (in J). x-direction from the origin to x = 4.63 m. Find the work W = J (b) What If? Find the work W = (4.63 m, 4.63 m) along a straight-line path making an angle of 45.0° with the positive x-axis. J F. dr done by the force on the object (in J) if it moves from the origin to Is the work done by this force dependent on the path taken between the initial and final points? dependent independent

You slide a box of books of mass 31 kg at constant speed up a 30°ramp, applying a force of 200 N directed up the slope. The coefficient of kinetic friction is 0.18. (a)How much work have you done when the box has risen 1 m vertically? (b)How much work was done by gravity? (c)How much work was done by friction?(d)What was the net work done on the box? Draw Free body diagram as well