Question

a car is moving on a straight road due north with a uniform speed of 50km/h when it turns left through 90* .If the speed remains unchanged after turning than the change of the velocity of car is

Answer 1

Let the North be represented by Y axis.  The when the car turns left, it moves along the -ve x axis, towards West.

Let $\vec{v1} = 50 \hat{j}\ kmph\ \ \ and,\ \vec{v2} = -50 \hat{i}\ kmph$

Change in velocity is = $\vec{v2}-\vec{v1}=-50\hat{i}-50\hat{j}\ kmph$

Magnitude of change in velocity=$\sqrt{50^2+50^2}=50\sqrt{2}$

Direction of the change in velocity = South west , 45 deg. from South towards West.