To save on heating costs, the owner of a greenhouse keeps 380 kg of water around in barrels. During a winter day, the water is heated by the sun to 19.5° C. During the night the water freezes into ice at 0.0° C in 6 hours. What is the minimum ampere rating of an electric heating system (120 V) that would provide the same heating effect as the water does?

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?

Amass attached to a spring is displaced from its equilibrium position by 5cm and released. the system then oscillates in simple harmonic motion with a period of 1s. if that same mass–spring system is displaced from equilibrium by 10cm instead, what will its period be in this case? a mass attached to a spring is displaced from its equilibrium position by and released. the system then oscillates in simple harmonic motion with a period of . if that same mass–spring system is displaced from equilibrium by instead, what will its period be in this case? a) 0.5sb) 2sc) 1sd) 1.4s