Which of the following best describes how greenhouse gases raise the average temperature of the earth? a
They allow more light to penetrate the atmosphere
b
They are naturally hotter than other, nongreenhouse gases
c
They allow in solar energy but prevent some of the infrared heat energy from leaving the atmosphere
d
They have a very high albedo, which traps heat energy

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?