Answer:
force exerted by Jet pack is 63 N on the astronaut
Step-by-step explanation:
As per Newton's II law we know that
Rate of change in momentum of the system is net force on it
so we have
![F = (\Delta P)/(\Delta t)](https://img.qammunity.org/2021/formulas/physics/high-school/ylo0fmhsohe2m2ytf7ge4lkc6knjl9lhbv.png)
so we have
![F = (m(v_f - v_i))/(\Delta t)](https://img.qammunity.org/2021/formulas/physics/high-school/awzv1ca4zga4njwqjio7hoab82axe458bm.png)
so we have
Since he used jet pack to return back towards the spaceship
so here we will have
![v_f = 7 m/s](https://img.qammunity.org/2021/formulas/physics/high-school/ro3k4a6xsfavqy6q6wozmvejxphklyls8p.png)
![v_i = -7 m/s](https://img.qammunity.org/2021/formulas/physics/high-school/w8vi1hv7o0r03my0s50e5z1fs2o2fj9w8p.png)
![F = (63(7 + 7))/(14)](https://img.qammunity.org/2021/formulas/physics/high-school/n9pf9ah8giqkx5wjn8bpzn4vyvt27hv6ox.png)
![F = 63 N](https://img.qammunity.org/2021/formulas/physics/high-school/llkh6c274vglbfag4c9q3kqd99vy68b4z3.png)
force exerted by Jet pack is 63 N on the astronaut