Question

A point which has velocities represented by 7, 8
and 13 is at rest. Find the angle between the
direction of two smaller velocities.
(1) 30°
(2) 45°
(3) 60
(4) 90°​

Answer 1

Answer:

60°

Explanation:

A point which has velocities represented by 7, 8

and 13 is at rest. Find the angle between the

direction of two smaller velocities.

As point is at rest so Resultant of two velocity would be opposite to third velocity

| 7  + 8 | = | 13|

Let say angle between 7 & 8  is α

7² + 8² + 2*7*8(Cosα)  = 13²

=> 49 + 64 + 112Cos² = 169

=> 112 Cosα = 56

=> Cosα = 56/112

=> Cosα = 1/2

=> α = 60°