A ball of mass 0.5 kg is attached to the end of a string having length...
T = mw²r
324 = 0.5 ×0.5×w²
w² = 324÷0.25
w = √1296
w = 36 rad/s
A ball of mass 0.5 kg is attached to the end of a string having length...
Given:
- Mass of ball, m = 0.5 kg
- Length of string, l = 0.5 m
- Maximum tension in string, T = 324 N
To find:
- Maximum angular velocity, ω in rad/s
Approach:
- We can use the equation for centripetal force, Fc = mv^2/r, where m is mass of the ball, v is velocity of the ball, and r is radius of circular path.
- The tension in the string provides the centripetal force required to keep the ball in circular motion.
- At maximum tension, T = Fc, so we can equate the two equations and solve for v.
- Then we can use the formula for angular velocity, ω = v/r, where r is the length of the string.
Solution:
1. Equating T and Fc:
- T = mv^2/r
- Substituting the given values: 324 = 0.5 * v^2 / 0.5
- Solving for v: v = sqrt(324*2) = 36 m/s
2. Finding angular velocity:
- ω = v/r
- Substituting the given value of r: ω = 36/0.5 = 72 rad/s
3. Checking if the answer is within bounds:
- We know that the tension in the string cannot exceed the maximum value, T = 324 N.
- The centripetal force required to keep the ball in circular motion is Fc = mv^2/r.
- At maximum tension, T = Fc, so we can set the two equations equal to each other and solve for v.
- If the calculated value of v exceeds the speed of light or any other physically impossible value, then the answer is incorrect.
- In this case, the value of v = 36 m/s is within reasonable bounds, so the answer is correct.
Therefore, the correct answer is option 'D', 36 rad/s.
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