As a portion of an workout routine to strengthen their pectoral muscles a man stretches a spring which has a spring constant k = 420 N/m. a)Write an equation for the work necessary to stretch the spring from the relaxed state to a distance x1.  b) Calculate the work in joules required to stretch the springs from their relaxed state to the position x1 = 51 cm.  c)   Write an equation for the work necessary to stretch the spring from the position x1 to x2  and Calculate the work in joules required to stretch the spring from x1 = 51 cm to x2 = 75 cm

Two children have identical spring-loaded catapults, which contain springs with spring constant k. If Samir compresses the spring in his catapult by a distance x and Mona compresses hers by a distance 2x, how does the work they have done to compress their catapults compare? A. Mona has done 2 times as much work as Samir. B. Samir has done 2 times as much work as Mona. C. They have done the same amount of work. D. Mona has done 4 times as much work as Samir.

1. A roller-coaster car with a mass of 1200 kg starts at rest from a point 20 m above the ground. At point B, it is 9 m above the ground. [Express your answers in kilojoules (kJ).] a. What is the initial potential energy of the car? b. What is the potential energy at point B? c. If the initial kinetic energy was zero and the work done against friction between the starting point and point B is 40 000 J (40 kJ), what is the kinetic energy of the car at point B 2. The time required for one complete cycle of a mass oscillating at the end of a spring is 0.80 s. What is the frequency of oscillation?

A spring scale that reads in grams uses a 10.0-cm-long spring. Hanging a water bottle from the scale stretches the spring to 11.5 cm and causes the scale to read 450 g. What is the elastic potential energy of the stretched spring? Express your answer with the appropriate units. Usp = Submit μÀ Value Request Answer Units ?

An object with a mass of 15kg slides down an incline with a length of 6.0m at an angle of 28 degrees from horizontal.  The coefficient of friction between the object and incline is 0.25  a) How much work does the gravitational force perform on the object? b) How much work does the frictional force perform on the object?  c) What will its speed be as it reaches the bottom of the incline?

Which of the following statements are true?   options:   The rest length of a spring is where it applies zero force.   The spring constant has units of N/m.   Work can be calculated for a force that depends on position.   Work is the slope of the force vs. position graph.   If we stretch a spring twice as far beyond the rest length, the spring force is 4x larger.   If we stretch a spring twice as far beyond the rest length, the potential energy is 4x larger.

The force on a particle is directed along an x axis and given by F = Fo(x/xo - 1) where x is in meters and F is in Newtons. If Fo= 1.5 N and Xo = 5.8 m, find the work done by the force in moving the particle from x = 0 to x = 2x0 m. Number i Units