NEETPhysicsMotion in Two Dimensions
Two athletes are running on concentric circular tracks of radii R and 2R . They start simultaneously and complete one full lap at the exact same instant. The ratio of their linear speeds is:
Options
- A1:1
- B2:1
- C1:2
- D1:4
Correct answer
C. 1:2
Step-by-step solution
Since both athletes complete one full lap in the same time, their time periods T are equal. Angular speed is given by = 2 T . Since T is the same, is the same for both athletes. The linear speed is related to angular speed by v = r . Therefore, the ratio of their linear speeds is v₁ v₂ = R (2R) = 1 2 , which is 1:2 . Answer: 1:2