Springs and Forces

A spring of negligible mass stretches 3.00 cm from its relaxed length when a force of 6.20 N is applied. A 1.200 kg particle rests on a frictionless horizontal surface and is attached to the free end of the spring. The particle is pulled horizontally so that it stretches the spring 5.00 cm and is then released from rest at t=0. ...continues

Springs and Forces

A child's toy consists of a piece of plastic attached to a spring. The spring is compressed against the floor a distance of 2.00 cm, and the toy is released. If the toy has a mass of 90 g and rises to a maximum height of 50.0 cm, estimate the force constant of the spring (in N/m). I need help on which equation/formula to use a ...continues

spring constant of bungee cord

"A 61.2 kg bungee jumper jumps from a bridge. She is tied to a 11.2 m long (unstretched) bungee cord and falls a total of 32.4 m. Calculate the spring constant k of the bungee cord." Here's how I approached this question: (1/2)(k)(x^2) = mgH k = 2mgH/x^2 k = (2)(61.2)(9.8)(32.4)/11.2^2 = 309.8 N/m But this is not the ...continues

KE/PE

"In the high jump, the kinetic energy of an athlete is transformed into gravitational potential energy without the aid of a pole. With what minimum speed must the athlete leave the ground in order to lift his center of mass 2.00 m and cross the bar with a speed of 0.670 m/s?" Thank you!

Energy lost due to friction

"A 25.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 20.00 m. When she is partway down the slide, at a height h2 of 8.00 m, she is moving at a speed of 8.90 m/s. Calculate the mechanical energy lost due to friction (as heat, etc.)."

Magnitude of resultant forces

Mathematically and graphically determine the magnitude of the resultant forces acting on point (A) as shown in the figure below. Do not use mathematics in your graphical solutions.

Momentum and velocity

An object of mass 2 kg travelling in a straight line with a velocity of 20m/sec collides with, and strikes to, a stationary object of mass 3 kg. They both move off together in the same straight line with a velocity of v m/sec. If no external forces are acting calculate a. the total momentum just before the impact b. the tot ...continues

Work/kinetic friction on a system moving at constant speed.

"A 276 kg piano slides 4.02 m down a 30.2° incline and is kept from accelerating by a man who is pushing back on it parallel to the incline, as seen in the figure (attached in a Word file). The effective coefficient of kinetic friction is 0.400. Calculate the work done by the man on the piano." See attached file for full prob ...continues

average force

"A 74.3 kg man steps out a window and falls (from rest) 1.01 m to a sidewalk. If the man falls with his knees and ankles locked, the only cushion for his fall is a 0.488 cm give in the pads of his feet. Calculate the average force exerted on him by the ground in this situation. This average force is sufficient to cause cartilage ...continues

Spring problem

A 2 kg block slides along a frictionless tabletop at 8.0 m/s toward a second block (at rest) of 5 kg. A spring which obeys Hooke's law with a spring constant k = 850 N/m, is attached to the second block. (a) What will be the maximum compression of the spring? (b) What will be the velocities of the two blocks when the spring i ...continues