Q 16.     An object of mass 100 kg is accelerated uniformly from a velocity of 5 m s-1 to 8 m s-1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

Answers (1)
S Sanket Gandhi

The momentum is given by : 

                                              p\ =\ mv

 Initial momentum is :            p_i\ =\ mu\ =\ 100\times 5\ =\ 500\ Kg\ m/s

And the final momentum is :

                                                         p_f\ =\ mv\ =\ 100\times 8 \ =\ 800\ Kg\ m/s

Also, the force is defined as rate of change of momentum.

Thus                                                 F\ =\ \frac{p_f\ -\ p_i}{t}

or                                                            =\ \frac{800\ -\ 500}{6}\ =\ 50\ N

Hence the force exerted on the body is 50 N. 

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