Physics Two Dimensional Motion Question 283

Question: A boy on a cycle pedals around a circle of 20 metres radius at a speed of $ 20,metres/\sec . $ The combined mass of the boy and the cycle is 90 kg. The angle that the cycle makes with the vertical so that it may not fall is $ (g=9.8,m/{{\sec }^{2}}) $

[MP PMT 1995]

Options:

A) $ {{60.25}^{o}} $

B)$ {{63.90}^{o}} $

C) $ {{26.12}^{o}} $

D)$ {{30.00}^{o}} $

Show Answer

Answer:

Correct Answer: B

Solution:

$ \tan \theta =\frac{v^{2}}{rg}=\frac{400}{20\times 9.8} $

Therefore $ \theta =63.90{}^\circ $