Show that if , then angle between the two vectors is greater than
Let be the angle between .
Here, we have
∴
That is,
Since is negative, therefore
, is the angle between the two vectors.
A particle is moving in a circle of radius r centred at O with constant speed v. Find the magnitude of change in velocity moving from A to B
Let be the velocities of particle at A and B.
Since the speed of the particle () is constant.
Therefore,
As angle therefore angle between the velocity vectors is also
Now,
=
This is the required change in magnitude of the velocity on moving from A to B.
If is the angle between , then show that
On evaluating
Therefore,