alleryA stone of mass 0.5 kg is whirled in a horizontal circle of radius 1 m at constant angular speed 4 rad s⁻¹ by a string. The tension in the string is:
A2 N
B4 N
C8 N
D16 N
Answer & Solution
Correct answer: C. 8 N
1. For uniform circular motion the only horizontal force is the tension, providing the centripetal force.
2. Centripetal acceleration = ω² r = 4² × 1 = 16 m s⁻².
3. T = m ω² r = 0.5 × 16 = 8 N.
4. Wrong picks come from forgetting to square ω (gives 2 N) or doubling (16 N).
_Source: syllabus Physics Ch 4 "Laws of Motion", §4.10 Circular Motion, p. 62_
Keep practising Laws of Motion
Browse all Laws of Motion questions for AP Intermediate 1st Year, or explore more Physics topics.
Related questions
A constant force of 6 N acts for 4 s on a 2 kg body initially at rest. The kinetic energy A car of mass 1000 kg accelerates from rest to 20 m s⁻¹ in 5 s on a level road. The net hoA force F acts on a particle making an angle θ with its instantaneous velocity. The componNewton's second law is often written as F = m a. This form is strictly valid when:A batsman hits a 0.15 kg ball back along the line of approach without changing its speed oMomentum p of a body of mass m moving with velocity v is defined as:The SI unit of force, the newton, is defined as the force that:Newton's first law of motion is essentially a statement of: