The earth exerts a downward force of 850 N on a veteran astronaut as he works outside the space shuttle. What force (if any) does the astronaut exert on the earth?
Don't forces always have equal and opposite forces? Newtons third law says something about that.
When you stand on a scale, and it reads 100 lbs. Turn it upside down, let the Earth read its weight: 100 lbs, in the opposite direction.
To determine the force that the astronaut exerts on the Earth, we can apply Newton's third law of motion, also known as the law of action and reaction. According to this law, for every action, there is an equal and opposite reaction.
In this case, the force exerted by the Earth on the astronaut is 850 N downward. Following Newton's third law, the force exerted by the astronaut on the Earth will be an equal magnitude force but in the opposite direction. Therefore, the force exerted by the astronaut on the Earth will also be 850 N, but in the upward direction.
So, the astronaut exerts an upward force of 850 N on the Earth.