Verified Solution • 2025–26 Session moderate

QJEEM23Phd45b: JEE Main 2023 Physics - Class 11 JEEM23Phd45b Solution: A child of mass is going round a merry-go-round that makes 1…

A child of mass 5 kg5 \mathrm{~kg} is going round a merry-go-round that makes 1 rotation in 3.14 s3.14 \mathrm{~s} . The radius of the merry-go-round is 2 m2 \mathrm{~m} . The centrifugal force on the child will be

Multiple Choice Options

  • A 50 N
  • B 80 N
  • C 100 N
  • D 40 N

Step-by-Step Verified Solution

To calculate the centrifugal force acting on the child, we need to find the angular velocity of the merry-go-round and then apply the formula for centrifugal force.

The merry-go-round makes 1 rotation in 3.14 seconds, so its angular velocity ( ω\omega ) can be calculated as:

ω=2πT\omega = \frac{2\pi}{T} , where TT is the time period for one rotation.

ω=2π3.14=2 radians/s\omega = \frac{2\pi}{3.14} = 2 \, \text{radians/s}

Now, the formula for centrifugal force ( FF ) is:

F=m⋅r⋅ω2F = m \cdot r \cdot \omega^2 , where mm is the mass of the child, rr is the radius of the merry-go-round, and ω\omega is the angular velocity.

F=5 kg⋅2 m⋅(2 radians/s)2=5 kg⋅2 m⋅4 (radians/s)2F = 5\,\text{kg} \cdot 2\,\text{m} \cdot (2\,\text{radians/s})^2 = 5\,\text{kg} \cdot 2\,\text{m} \cdot 4\,(\text{radians/s})^2

F=40 NF = 40\,\text{N}

Therefore, the centrifugal force on the child is 40 N40\,\text{N} .

Related Learning Resources & Exam Preparation