A
79 at time t=0, a rock
climber accidentally allows a
piton to fall freely from a high
point on the rock wall to the val-
ley below him. then, after a
short delay, his climbing partner,
who is 10 m higher on the wall,
throws a piton downward. the
positions y of the pitons versus t
during the falling are given in
fig. 2-40. with what speed is the
second piton thrown?
0
3
1 2
t(s)
fig. 2-40 problem 79.

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.

What is the relationship between globular clusters and the milky way?