A constant couple of 400 N m turns a wheel of moment of inertia 100 kg m2 about an axis through its centre. The angular velocity gained in 4 s is

We know that relation between torque and angular acceleration isτ=Iα,So α=τI=400100=4rads−2now ω=ω0+αthereω0= initial angular velocity =0So ω=αt=(4)(4)=16rads−1