Laws Of Motion Question 18
Question: Assertion: Linear momentum of a body changes even when it is moving uniformly in a circle. Reason: Force required to move a body uniformly along a straight line is zero.
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: B
Solution:
In uniform circular motion of a body the speed remains constant but velocity changes as direction of motion changes. As linear momentum = mass × velocity, therefore linear momentum of a body changes in a circle. On the other hand, if the body is moving uniformly along a straight line then its velocity remains constant and hence acceleration is equal to zero. So force is equal to zero.
