Abumblebee buzzes past you at 3 m/s. the frequency of the hum made by its wings is 152 hz. assume the speed of sound to be 342 m/s. what is the observed frequency of the hum as the bumblebee approaches you?
according to einstein's special theory of relativity, the speed of the light in a vacuum is the same no matter the speed with which an observer travels. so the answer should be a) 0,1c (1/10 the speed of light)
all of the potential energy = kinetic energy.
so your answer is 665 j
mass of the bullet (m) = 25 g = 0.025 kg,
mass of the gun (m) = 0.9 kg,
speed of the bullet (v) =230 m/s,
speed of the bullet (v) = ?
from the given data it is clear that, the momentum is conserved. according to "law of conservation of momentum" the total momentum before and after the collision is equal.
in this problem the momentum before collision (bullet+gun) is zero.
therefore, after the gun fires a bullet, the momentum must be zero.
m × v + m × v = 0
m × v = momentum of the gun
m × v = momentum of the bullet
(0. 9 × v) + (0.025 × 230) = 0
0.9 v = -5.75
v = -5.75/0.9
= -6.39 m/s
the gun recoils with a speed of 6.39 m/s
the answer is in fact true