NTA Abhyas JEE Main2020PhysicsMotion in Two DimensionsPractice
A cyclist is moving with a constant acceleration of 1 . 2 m s - 2 on a straight track. A racer is moving on a circular path of the radius 150 m at a constant speed of 15 m s - 1 . Find the magnitude of the velocity of racer which is measured by the cyclist has reached a speed of 20 m s - 1 for the position represented in the figure.
Options
- A18 .03 m s - 1
- B25   m   s - 1
- C20 m s - 1
- D15 m s - 1
Correct answer
A. 18 .03 m s - 1
Step-by-step solution
Let v → c = actual velocity of cyclist along x - a x i s v → r = the velocity of racer along tangent of circular path (shown in figure) ∴   v → r c =   v → r -   v → c Hence v → c = 20   i ^ v → r c = V r cos ⁡ 30 o j ^ + V r sin ⁡ 30 o i ^ Or v → r = 15 cos ⁡ 30 j ^ + 15 sin ⁡ 30 i ^ = 15 2 2   j ^ + 15 2   i ^ ∴ v → r c =   v → r -   v → c = 15 3 2   j ^ + 15 3 2