A ball is tied to a string and swung in a vertical circle. At the highest point
Practice Questions
Q1
A ball is tied to a string and swung in a vertical circle. At the highest point of the circle, what is the condition for the ball to remain in circular motion?
Tension must be zero
Tension must be maximum
Weight must be zero
Centripetal force must be zero
Questions & Step-by-Step Solutions
A ball is tied to a string and swung in a vertical circle. At the highest point of the circle, what is the condition for the ball to remain in circular motion?
Correct Answer: The weight of the ball must be equal to the required centripetal force.
Step 1: Understand that the ball is moving in a circle and needs a force to keep it moving in that circle. This force is called centripetal force.
Step 2: At the highest point of the circle, two forces act on the ball: its weight (downward) and the tension in the string (also downward if the string is taut).
Step 3: The weight of the ball is the force due to gravity, which pulls it down towards the ground.
Step 4: For the ball to stay in circular motion at the highest point, the total downward force (weight + tension) must equal the required centripetal force to keep it moving in a circle.
Step 5: If the tension in the string is zero, then the weight of the ball must provide all the necessary centripetal force.
Step 6: Therefore, the condition for the ball to remain in circular motion at the highest point is that the weight of the ball must be equal to the required centripetal force.
Centripetal Force – The net force required to keep an object moving in a circular path, directed towards the center of the circle.
Gravitational Force – The force acting on the ball due to gravity, which contributes to the centripetal force at the highest point of the circle.
Tension in the String – The force exerted by the string on the ball, which can be zero at the highest point if the gravitational force is sufficient.
