141665
Light from a source travels out with a velocity c. If the source moves away from the observer with a velocity \(v\), then the relative velocity of light with respect to observer is
1 \(\mathrm{c}\)
2 \(\mathrm{c}+\mathrm{v}\)
3 \(\mathrm{c}-\mathrm{V}\)
4 \(\sqrt{c^{2}+v^{2}}\)
Explanation:
A The speed of light is the same for any inertial reference, \(c=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\) So, it doesn't matter that how fast the source moves away from the observer. Thus, the relative velocity of light with respect to observer is \(\mathrm{v}=\mathrm{c}\)
AP EAMCET (17.09.2020) Shift-II
Motion in One Dimensions
141686
If a person sitting in a train moving with a constant velocity along a straight line, throws a ball vertically upwards, then :
1 ball will fall onwards the train
2 ball will return to thrower's hand
3 ball will not return to thrower's hand
4 none of the above
Explanation:
B When the ball is thrown in vertically upward direction and given that the train is moving up with a constant velocity. Therefore, the horizontal velocity of the train and ball are both same and the ball travels the same horizontal distance as that of the train. Therefore, the ball will come back into the hands of thrower.
141665
Light from a source travels out with a velocity c. If the source moves away from the observer with a velocity \(v\), then the relative velocity of light with respect to observer is
1 \(\mathrm{c}\)
2 \(\mathrm{c}+\mathrm{v}\)
3 \(\mathrm{c}-\mathrm{V}\)
4 \(\sqrt{c^{2}+v^{2}}\)
Explanation:
A The speed of light is the same for any inertial reference, \(c=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\) So, it doesn't matter that how fast the source moves away from the observer. Thus, the relative velocity of light with respect to observer is \(\mathrm{v}=\mathrm{c}\)
AP EAMCET (17.09.2020) Shift-II
Motion in One Dimensions
141686
If a person sitting in a train moving with a constant velocity along a straight line, throws a ball vertically upwards, then :
1 ball will fall onwards the train
2 ball will return to thrower's hand
3 ball will not return to thrower's hand
4 none of the above
Explanation:
B When the ball is thrown in vertically upward direction and given that the train is moving up with a constant velocity. Therefore, the horizontal velocity of the train and ball are both same and the ball travels the same horizontal distance as that of the train. Therefore, the ball will come back into the hands of thrower.
