Question 19: Work, Energy and Power & Circular Motion

Question

One end of the string of length $l$ is connected to a particle of mass $$m$$ and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed $$v$$, the net force on the particle (directed towards centre) will be ( $$T$$ represents the tension in the string)

Accepted Answer

Consider the string of length $$l$$ connected to a particle as shown in the figure
Speed of the particle is $$v$$. As, the particle is in uniform circular motion, the net force on the particle must be equal to centripetal force which is provided by the tension $$(T)$$.
$$\begin{aligned}
	herefore 	ext { Net force } & =	ext { Centripetal force } \
& =	ext { Tension in string }
\end{aligned}$$
$$\Rightarrow \quad \frac{m v^2}{l}=T$$

Answer

$$T$$

Answer

$$T+\frac{m v^2}{l}$$

Answer

$$T-\frac{m v^2}{l}$$

Answer

zero

Work, Energy and Power & Circular Motion

One end of the string of length l is connected to a particle of mass $m and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed v, the net force on the particle (directed towards centre) will be ( T$ represents the tension in the string)

Choose the correct answer: