2. A balloon contains 6 m3 of helium at a pressure of 100 kPa. As the balloon rises through
the atmosphere, the pressure falls and the balloon expands. Assuming that the
temperature does not change, what is the volume of the balloon when the pressure has
fallen to
a. 50 kPa
b. 40kPa? [4]

Agymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular velocity of 2rev/s. during the dismount she stretches out into the straight position, with a length of 1.5m, (assume she is a uniform rod through the center) for her landing. the gymnast has a mass of 50kg. what is her angular velocity in the straight position?

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

You are standing on a boat. which of the following strategies will make the boat start moving? a. pushing the mast b. throwing some cargo out of the boat c. pushing the front ofthe boat d. pushing another passenger