Kinematics Question 105
Question: Assertion : The average and instantaneous velocities have same value in a uniform motion. Reason : In uniform motion, the velocity of an object increases uniformly.
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: C
Solution:
An object is said to be in uniform motion if it undergoes equal displacement in equal intervals of time.
$ \therefore v _{av}=\frac{s _{1}+s _{2}+s _{3}+…}{t _{1}+t _{2}+t _{3}+…} $
$ =\frac{s+s+s+…}{t+t+t+…}=\frac{ns}{nt}=\frac{s}{t} $ and $ v _{ins}=\frac{s}{t}. $ Thus, in uniform motion average and instantaneous velocities have same value and body moves with constant velocity.
