Kinematics Question 28

Question: A scooter going due east at 10 ms?1 turns right through an angle of 90°. If the speed of the scooter remains unchanged in taking turn, the change it’s the velocity of the scooter it’s [BHU 1994]

Options:

A) $ 20.0m{s^{1}} $ south eastern direction

B) Zero

C) $ 10.0m{s^{1}} $ in southern direction

D) $ 14.14m{s^{1}} $ in south-west direction

Show Answer

Answer:

Correct Answer: D

Solution:

If the magnitude of vector remains same, only direction change by $ \theta $ then $ \overrightarrow{\Delta v}=\overrightarrow{v_2}-\overrightarrow{v_1} $ , $ \overrightarrow{\Delta v}=\overrightarrow{v_2}+(-\overrightarrow{v_1)} $

Magnitude of change in vector $ |\overrightarrow{\Delta v}|=2v\sin ( \frac{\theta }{2} ) $

$ |\overrightarrow{\Delta v}|=2\times 10\times \sin ( \frac{90{}^\circ }{2} ) $ = $ 10\sqrt{2} $ = $ 14.14m/s $

direction is south-west .



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