Question

The particle moves over there quarters of a circle of radius r. What is the displacement [a] √2 r [b]√2r [c] 3√r [d]√3 r

Answer 1

Answer:

Imagine this problem as a clock,

The hour hand and the minute hand are at 12.

Let's imagine that the hour hand remains intact while the minute hand completes 3 quarters and reaches 9.

The angle between the hour hand and minute hand is 90° (for magnitude only).

So by applying Pythagoras theorem,

Displacement= √(r^2 + r^2))

Which comes out to be r√2.