A person is using a pulley to lift a heavy platform. The person pulls on the cord with a force of 120 N. The person pulls it down a distance of 1.0 m. The platform is pulled up by a force of 153 N. It moves up 0.6 N. What is the efficiency of the pulley?

Write down two additional questions about earth's magnetic field that will make your presentation more informative.

How does the electric potential energy between two charged particles change if one particle is reduced by a factor of 3? a. increased by a factor of 3 b. it is decreased by a factor of 9 c. it is reduced by a factor of 3 d. it is increased by a factor of 9

In which situation is the acceleration of a car negative? question 5 options: a)the velocity of a car was 75 km/hr over 4 hours. b)the velocity of a car reduced from 50 km/hr over one minute. c)the velocity of a car increased from 40 km.h to 75 km/h over 15 minutes. d)the velocity of a car was 45 km/hr at 2: 00pm and at 4: 00pm its velocity was 85 km/ht.