A 20 kg box is resting on horizontal surface initially. Then a F = 50 N force pulls on the box by a cord at an angle of 20 degrees above horizontal. The kinetic frictional coefficient is 0.20. 1.What is the magnitude of acceleration of the box, a=? 2.What is the kinetic energy of the box after 3.0 seconds? (hint: calculate the velocity first v =?) 3.What is the work done by the force Fin 3.0 second? (hint: calculate the distance first, d = ?)

4. A 2.0 kg box slides down a ramp a distance of 3.0 meters before it reaches the ground. The ramp has an angle of 35°, and the force of kinetic friction if 4.0 N. a) What is the work done by gravity on the box? (include a FBD) b) What is the speed of the box at the bottom of the ramp?

An elevator is designed so that when it travels upward, it has constant acceleration from rest to its cruising speed of 2.0 m/s in a time of 4.0 seconds. The elevator has a mass of 625kg. Assume friction is ignored.  A. Determine the average power (in W) of the elevator motor while its accelerating upward to its cruising speed. B. Determine the motor power (in W) when the elevator is moving upward at its cruising speed.

Q30

A 265-kg load is lifted 18.0 m vertically with anacceleration a = 2m/s by a single cable.1. Determine the tension in the cablea. 2343N c. 3,543Nb. -2343N d. -3,543N2. Determine the net work done on the loada. 10,800 J c. 23,718 Jb. 63,774 J d. 52,974J3. Determine the work done by the cable on the loada. 10,800 J c. 23,718 Jb. 63,774 J d. 52,974J4. Determine the work done by the gravity on the loada. -10,800 J c. -23,718 Jb. -63,774 J d. -52,974J

A 6.30 kg block is pushed 9.40 m up a smooth 37.0 º inclined plane by a horizontal force of 76.0 N. If the initial speed of the block is 3.30 m/s up the plane. Calculate the initial kinetic energy of the block. Kinitial Submit Part B Submit Calculate the work done by the 76.0 N force. Part C We = VALO Requect Antwer Calculate the work done by gravity. Part D Requeci AntWar Submit Requect Answer WN = Calculate the work done by the normal force. + 10 ca 1? 17

1. How much work was done by a machine that exerts a 5000 N force to compress a 10-meter-long steel bar so it becomes 3 meters in length. 2. Find the angle between the 500 N applied force and the 3-meter displacement if the work done is 1500 Joules. Hiii please write a solution thank you

2. A 3.00 kg object is initially at rest on a horizontal surface. An applied force acts on the object in the +x-direction. Assume there is friction in the system as well. The Net Work done on the object is 50.0 J over a distance of 7.00 m. a) What is the object's Change in Kinetic Energy? Do Not Overthink this! b) What Net Force acted on this object?

A3

A horizontal force of 150 N is applied to push a 40.0 kg box a distance 6.00 m on a rough horizontal surface. If the box moves quickly constant, determine: A. The work that reverses the 150 N force. B. The coefficient of kinetic friction between the box and the surface.