some people agree that wearing seat belts reduces the risk of injurt to people in the car. however they say that the risk to oth
1 answer:
You might be interested in
Answer:
For the first situation, we first need to find the mass of the second train car.
In order to do that, we apply the conservation of the amount of movement:
and we have as a result:
m2 = 289.6875
For the second situation, also we will apply the conservation of the amount of movement:
and we have as a result:
V = 2.64 (it is moving to the right)
Answer:
The Doppler Effect is given by the following relation;
Where;
f' = The frequency the observer hears
f = Actual frequency of the wave
v = The velocity of the sound wave
= The velocity of the observer
= The velocity of the source
Where the observer is stationary, we have;
(i) When the source is moving in the direction of the observer
(ii) When the source is receding from the observer, we have;
Therefore;
(a) A person left behind on the platform
For a person left behind on the platform, we have that the radio source is receding, therefore, we have;
(1) Given that (v + ) > v, therefore, v < (v +
), f' < f, the frequency heard by the person left on the platform, f', is smaller (lower) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively smaller
(b) A person down below floating on a rubber raft
For the the person down below on the rubber raft, the radio source is advancing
Therefore, the radio source is moving towards the person at rest down on the rubber raft, therefore, we have;
(1) Given that (v - ) < v, therefore, f' > f, the frequency heard by the person down below floating on the rubber raft, f', is greater (higher) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively greater (higher)
Explanation: