plz help!!


A group of students performed an experiment to prove the law of conservation of energy. In the experiment, a flask containing water at room temperature was shaken vigorously for a few minutes. The table shows a partial record of the temperature of the water before and after shaking.

Experimental Record
Temperature
Before Shaking 21 °C
After Shaking Unknown


What best predicts the unknown temperature? (3 points)

Less than 21 °C because heat energy is formed from the energy used in shaking

Greater than 21 °C because heat energy is formed from the energy used in shaking

Less than 21 °C, because the total energy of the system after shaking is higher than before shaking

Greater than 21 °C, because the total energy of the system after shaking is higher than before shaking
9.
(01.04 HC)

The table shows the potential energy and kinetic energy of a skier at two different positions on a hill.

Position and Energy
Position (above ground) Kinetic Energy Potential Energy
100 meters 0 units 50,000 units
60 meters ? 30,000 units


What is the kinetic energy of the skier at a height of 60 meters above ground? (3 points)

20,000 units, because total energy remains unchanged

80,000 units, because total energy remains unchanged

20,000 units, because total energy of the skier decreases

80,000 units, because total energy of the skier decreases