question_answer

The motion of a body of mass 5 kg is shown in the v-t graph. Find from graph. (i) it acceleration. (ii) the force acting on the body (iii) the change in momentum of body in 2 seconds after start.

Answer:

                               (i) Acceleration = slope of the line of v-t graph \[=\frac{5}{2}=\frac{10}{4}=\frac{15}{6}=2.5\,\text{m/}{{\text{s}}^{\text{2}}}\] (ii) The force acting on the body is given by \[F=ma=5\times 2.5=12.5\text{N}\] (iii) \[u=0,\upsilon =5m/s,t=2s\] Thus, change in momentum = mv - mu \[=5\times 5-5\times 0=25\,\text{kg}\,\text{m/s}\]