Question
An 58.0 N box of clothes is pulled 5.2 m up a 30.0° ramp by a force of 95 N that points along the ramp. If the coefficient of kinetic friction between the box and the ramp is 0.22, calculate the change in the box's kinetic energy.
Answers
drwls
The work done by the applied force is 95 x 5.2 = 494 J
Part of the work was done overcoming the friction force. The friction force is
Ff = 58*0.22*cos30 = 11.05 N and the work done against that force is 57.5 J
The work done increasing the gravitational potential energy is:
M*g*5.2*sin 30 = 150.8 J
That leaves a total of 494 - 57.5 - 150.8 J avaialbkle to increase kinetic energy
Part of the work was done overcoming the friction force. The friction force is
Ff = 58*0.22*cos30 = 11.05 N and the work done against that force is 57.5 J
The work done increasing the gravitational potential energy is:
M*g*5.2*sin 30 = 150.8 J
That leaves a total of 494 - 57.5 - 150.8 J avaialbkle to increase kinetic energy
brittany
your awesome! but where did you get the 95 in the first equation?
drwls
95 N is the pulling force, which they tell you. That multiplied bhy the distance pulled is the work done by that force.
Thanks for the kind words; you'd better check my numbers anyway.
Thanks for the kind words; you'd better check my numbers anyway.
brittany
oh haha! sorry didn't see it
audrey
uhm where did you get 57.5? and what is M & g????
Bailey
An 70.0 N box of clothes is pulled 24.0 m up a 30.0° ramp by a force of 115 N that points along the ramp. If the coefficient of kinetic friction between the box and ramp is 0.22, calculate the change in the box's kinetic energy.