A dumb-bell consists of two identical small balls of mass 1/2 kg each connected to the two ends of a 50 cm long light rod. The dumb-bell is rotating about a fixed axis through the centre of the rod and perpendicular to it at an angular speed of 10 rad/s. An impulsive force of average magnitude 50 N acts on one of the masses in the direction of its velocity for 0.10 s. Find the new angular velocity of the system.
The new angular velocity of the system is 
Given
The masses of the dumb-bells are both 500g attached at 50cm rotated at the center at an angular speed of 10 rad/s with a force of 5N for 0.10 sec
Formula used
The formula used is same as that of the formula for the relationship of velocity and acceleration in basic kinematics.
where
The initial velocity of the motion is denoted by ω and the final velocity is denoted by ω0
Explanation
Calculating the torque of the rotating dumb-bells we get
Now changing the implementation of torque in terms of force we get the angular acceleration as:
To find the angular speed of the rotating dumb-bell, put the value in the equation we get,
Therefore, the angular velocity of the rotating dumb-bell is calculated as 
.