A spring that obeys Hooke's law is hung in a vertical orientation. The spring is stretched a total of 6.0 cm from its equilibrium length when a 2.0 kg mass hangs from it. The spring, mass system is then pulled downward by an external force which lengthens the spring an additional 10cm. While the spring is being extended what is the work done by the spring?

1) A box of mass m= 50kg which is sliding on a horizontal rough surface and momentarily comes to stop after compressing the spring by a distance of 120 mm. The spring has a spring constant k = 20KN/m and is initially in its equilibrium state. The initial speed of the box is 3.0m/s. a) What is the work done by the spring as the box is brought to a stop? b) Write an expression for the work done by friction during the stopping of the box (in terms of the coefficient of kinetic friction). c) Determine the coefficient of friction between the box and the surface. v=3.0 ms 600 mm 600 mm 120 mm-

A mass m = 12 kg rests on a frictionless table and accelerated by a spring with spring constant k = 5182 N/m. The floor is frictionless except for a rough patch. For this rough path, the coefficient of friction is H = 0.48. The mass leaves the spring at a speed v = 3.1 m/s. 1) How much work is done by the spring as it accelerates the mass? 2) How far was the spring stretched from its unstreched length? 3) The mass is measured to leave the rough spot with a final speed v; = 1.8 m/s. How much work is done by friction as the mass crosses the rough spot? 4) What is the length of the rough spot? 5) In a new scenario, the block only makes it (exactly) half-way through the rough spot. How far was the spring compressed from its unstretched length? 6) In this new scenario, what would the coefficient of friction of the rough patch need to be changed to in order for the block to just barely make it through the rough patch? (Use the compression of the spring that you just found in (5), for the…

3. Suppose you have an object attached to a bizarre spring, initially located at x = 0, the equilibrium point of the force of the spring on the object is given by F₁ = kx, S where k is a spring constant. (a) You displace the object from x = 0 to ₁ > 0, holding the object steady at the beginning and end. What is the work done by the spring? What is the work done by you? (b) You let go of the spring and observe the object move from location. x₁ to x2. Is x2 less than or greater than ₁? (c) What is the kinetic energy of the object at x2? (d) Is this bizarre spring realistic? Explain.

A trunk of mass m = 0.6 kg is pushed a distance d = 30 cm up an incline with an angle of inclination theta = 23.0° by a constant horizontal force P = 425 N (see figure). The coefficient of kinetic friction between the trunk and the incline is 0.31. P. Calculate the work done on the trunk by the applied force P. Calculate the work done on the trunk by the frictional force. Calculate the work done on the trunk by the gravitational force.

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

In the arrangement of the first figure, we gradually pull the block from x = 0 to x = +3.0 cm, where it is stationary. The second figure gives the work that our force does on the block. The scale of the figure's vertical axis is set by Ws = 1.0 J. We then pull the block out to x = +6.0 cm and release it from rest. How much work does the spring do on the block when the block moves from xi = +6.0 cm to (a) x = +4.0 cm, (b) x = -1.0 cm, and (c) x = -6.0 cm?

A 300-g block is dropped onto a vertical spring with spring constant k =180.0 N/m. The block becomes attached to the spring, and the spring compresses 44.8 cm before momentarily stopping. A). While the spring is being compressed, what work is done on the block by its weight? B). While the spring is being compressed, what work is done on the block by the spring force? C). What is the speed of the block just before it hits the spring? (Assume that friction is negligible.) D).If the speed at impact is doubled, what is the maximum compression of the spring?

7. The force of an ideal spring is given by F = -k x Where k is the spring constant of the spring and x is the displacement of the spring from equilibrium. To stretch a certain spring 3.00 cm from its unstretched length, 12.0 J of work must be done. a. What is the force constant of this spring? b. What magnitude force is needed to stretch the spring 3.00 cm from its unstretched length? c. How much work must be done to compress this spring 4.00 cm from its unstretched length, and what force is needed to compress it this distance?

A pendulum with a light string and a mass attached to it. As the pendulum swings downward. What is the work done by the strings tension on the mass (+, - or 0) and why?