Answer:
1) The magnitude of change in momentum is 7.695 kgm/s.
Explanation:
We know that momentum of a particle with mass 'm' travelling with a speed of 'u' is mathematically given by
[tex]\overrightarrow{p}=m\overrightarrow{u}[/tex]
Thus according to the given values initial momentum of the ball is
[tex]p_{1}=0.057kg\times 70m/s=3.990kgm/s[/tex]
The final momentum of the ball after bouncing off becomes
[tex]p_{2}=0.057kg\times -65m/s=-3.705kgm/s[/tex]
Thus the change in momentum is given by:
[tex]\Delta p=p_{2}-p_{1}\\\\=-3.705-3.990=-7.695kgm/s[/tex]
Thus the magnitude of change in momentum is 7.695 kgm/s.