15. A 2.1 kg rock is dropped from a height of 4.7 meters. What is the kinetic energy of the rock as it reaches the ground?
A. 46j
B. 72j
C. 97j
D. 145j

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.

Scientist have use computer models to create a series of maps that show how susceptible coastal cities in island countries are to the sea rising at different levels. the map shows that a 1 meter rise would swap cities all along the us eastern seaboard. a 6-meter sea level rise with sub merge a large part of florida. thermal expansion has already raise the oceans 10 to 20 centimeters the most likely cause, directly and indirectly, for such a rise in sea level is