As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff ideal springs arranged side by side so that they are parallel to each other. When you push the platform, you compress the springs. You do 80.0 J of work when you compress the springs 0.200 m from their uncompressed length. (a) What magnitude of force must you apply to hold the platform in this position? (b) How much additional work must you do to move the platform 0.200 m farther, and what maximum force must you apply?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff ideal springs arranged side by side so that they are parallel to each other. When you push the platform, you compress the springs. You do 75.0 J of work when you compress the springs 0.220 m from their uncompressed length. a) What magnitude of force must you apply to hold the platform in this position? b) How much additional work must you do to move the platform 0.220 m farther?  c) What maximum force must you apply to move the platform to the position in Part B?

A water-skier is being pulled by a tow rope attached to a boat. As the driver pushes the throttle forward, the skier accelerates. A 73.5-kg water-skier has an initial speed of 5.2 m/s. Later, the speed increases to 12.2 m/s. Determine the work done by the net external force acting on the skier. W =

As a segment of an workout regiment to toughen their pectoral muscles, a man stretches a spring which has a spring constant k=605N/m. a) If x=0 corresponds to when the springs are at their relaxed state, which image best represents the magnitude of the force applied to the springs as a function of the stretch distance (see image). b) Write an equation for the work necessary to stretch the spring from the relaxed state to a distance x1. c) Calculate the work, in joules, required to stretch the spring from its relaxed state to the position x1=59.7cm d) Write an equation for the work necessary to stretch the spring from the position x1 to position x2. e)  Calculate the work, in joules, required to stretch the spring from x1=59.7cm to x2=96.8cm.

A block of mass m = 4.00 kg is pushed a distance d = 2.50 m along a frictionless horizontal table by a constant applied force of magnitude F = 16.0 N directed at an angle θ = 28.0° below the horizontal as shown in the figure below. (a) Determine the work done on the block by the applied force. (b) Determine the work done on the block by the normal force exerted by the table. (c) Determine the work done on the block by the force of gravity. (d) Determine the work done by the net force on the block.

A 59 kg rollerblader skates across a skating rink floor. The graph below shows the net external force component acting on the skater along the displacement as a function of the magnitude of the displacement d.   the work done (in J) by the force on the rollerblader as he moves from 0 to 20.0 m   the work done (in J) by the force acting on the rollerblader from 20.0 m to 30.0 m

A cart is pulled a distance D on a flat, horizontal surface by a constant force F that acts at an angle θ with the horizontal direction. The other forces on the object during this time are gravity ( Fw ), normal forces ( FN1 ) and ( FN2 ), and rolling frictions Fr1 and Fr2 , as shown below. What is the work done by each force?

A 325 N force is pulling on an 85.0 kg refrigerator as it slides across a horizontal floor. The force acts at an upward angle of 25.0° above the horizontal. The coefficient of kinetic friction between the refrigerator and the floor is 0.150, and the refrigerator moves a distance of 5.50 m. Find (a) the work done by the pulling force, (b) the work done by the force of kinetic friction, (c) the net amount of work done on the refrigerator, and (d) if the refrigerator was initially at rest determine the speed of the refrigerator after the 5.50m displacement. (e) Include a force (or free-body) diagram of the situation. [Diagram 2 pts.]

A 5.8 kg body is at rest on a frictionless horizontal air track when a constant horizontal force F acting in the positive direction of an x axis along the track is applied to the body. A stroboscopic graph of the position of the body as it slides to the right is shown in the figure. The force F is applied to the body at t = 0, and the graph records the position of the body at 0.50 s intervals. How much work is done on the body by the applied force F between t = 0 and t = 1.0 s? t = 0 -0.5 s -1.0 s -1.5 s -2.0s 0.4 x (m) 0.2 0.6 0.8

A stone used in the sport of curling has a mass of 18.0 kg and is initially at rest, sitting on a flat horizontal ice surface. It is pushed with a constant horizontal force of magnitude 24.0 N over a distance of 4.00 m.  Starting from your calculated values for acceleration and final speed, calculate the duration of the bush. Compare this with the time calculated from the average power supplied during the push and the amount of work done.