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 20,000 units ?
What is the potential energy of the skier at a height of 60 meters above the ground?

Group of answer choices

30,000 units, because total energy decreases

70,000 units, because total energy decreases

30,000 units, because total energy remains unchanged

70,000 units, because total energy remains unchanged

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 2 options: the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the cold balloon expands and rises. the warm balloon shrinks and sinks. the warm balloon expands and rises. the cold balloon shrinks and sinks.

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?

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity