Physics: Sofa pushed up ramp?
A sofa is mounted on rollers so that it moves with negligible friction. Pushing that sofa up a ramp from the street onto a moving van, a worker does 1600 joules of work on the sofa. Yet, the sofa gains only 100 joules of kinetic energy; it’s not moving too fast at the top of the ramp.
A) How is this possible?
B) Is energy conservation violated here? Please explain.
Answers & Comments
Verified answer
it does'nt gain that much energy so you just look upon the energies first and even its not violated.
The sofa does not gain 100 joules of kinetic energy. It gains 100 joules of gravitational potential energy. This difference is important -- look it up in your textbook.
Energy conservation is not violated. The 1600 joules was "spent" on moving the sofa in both a horizontal and a vertical direction. The 100 joules only comes from force applied in a vertical direction.
Sorry if i say anything stupid. However... i know joule is some measurement of force. I don't know how much a "joule" is. so im assuming its a lot and that man is really strong. Only thing i can think is a steep ramp that has a lot of work pushing down?