Answer:
344.8 Hz
Explanation:
The frequency of a wave is given by:
where
v is the speed of the wave
is its wavelength
Here we have
v = 793 m/s
Substituting into the equation, we find
Answer:
<em>1. c. Same in both</em>
<em>2. a. Case 1</em>
<em></em>
Explanation:
1. The balls are identical in all sense, which means that if they are dropped from the same height, they should posses the same kinetic energy just before they collide with either the concrete floor or the stretchy rubber. Also, since they reach the same height when they bounced of the concrete floor or the piece of stretchy rubber, it means that they posses the same amount of kinetic energy at this point. Since their kinetic energy at these two points are the same, and they have the same masses, then this means that their momenta at these two instances will also be equal. Since all these is true, then the change in the momentum of the balls between the instance just before hitting the concrete floor or the stretchy rubber material and the instant the ball just leave the floor or the stretchy material is the same for both.
2. The ball that falls on the concrete will experience the greatest force, since the time of impact is small, when compared to the time spent by the other ball in contact with the stretchy rubber material; which will stretch, thereby extending the time spent in contact between them.
Answer:
The velocity of the astronaut is, v = - 0.36 m/s
Explanation:
Given data,
The mass of the astronaut, M = 84 kg
The mass of the gas expelled by the thruster, m = 35 g
= 0.035 g
The velocity of the gas expelled, v = 875 m/s
According to the conservation of momentum,
MV + mv = 0
V = - mv / M
Substituting the values,
V = - 0.035 x 875 / 84
= - 0.36 m/s
The negative sign in the velocity indicates the astronaut moves opposite to the direction of velocity of gas.
Hence, the velocity of the astronaut is, v = - 0.36 m/s
