A boulder with a mass of 25 kilograms slides 30 meters to the right while experiencing a rightward applied force of 150 newtons and a leftward force of friction that is two thirds the magnitude of the applied force.
1. Calculate the magnitude of work done by the force of friction.
A. O joules
B. 1500 joules
C. 3000 joules
D. 4500 joules

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

vapour or gas assuming atmospheriv pressure

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.