Circular motion in a vertical plane Quiz

1. A particle on a string of length $1$ m moves in a vertical circle. Find the least speed at the lowest point for a complete circle. ($g=9.8$)

• A. $4.43$ m s⁻¹
• B. $6.26$ m s⁻¹
• C. $7.00$ m s⁻¹
• D. $9.90$ m s⁻¹

2. A bead is threaded on a smooth circular wire of radius $1$ m. Find the least speed at the lowest point for a complete circle. ($g=9.8$)

• A. $6.26$ m s⁻¹
• B. $7.00$ m s⁻¹
• C. $4.43$ m s⁻¹
• D. $3.13$ m s⁻¹

3. A $0.5$ kg particle on a string of length $0.4$ m passes the top with speed $3$ m s⁻¹. Find the tension there. ($g=9.8$)

• A. $11.3$ N
• B. $6.35$ N
• C. $16.2$ N
• D. $4.90$ N

4. A particle on a string has $u^2=3gL$ at the lowest point. What happens?

• A. It completes the circle
• B. It oscillates below the horizontal
• C. It stops at the top
• D. The string goes slack above the level of $O$

5. A particle on a string of length $0.5$ m has speed $3$ m s⁻¹ at the lowest point. Find the greatest height above the lowest point. ($g=9.8$)

• A. $0.92$ m
• B. $0.50$ m
• C. $0.46$ m
• D. $0.23$ m