Can we move our arm in a perfectly friction-less world?
Answers
Answered by
0
I think we can't. Because for throwing, we primarily need to move some part of our body (for example our arm). And I think we cannot (or maybe we shouldn't) move some part of our body in a perfectly friction-less world. Because according to the first law of Newton ( "A body maintains its state of motion unless unbalanced external force acts up on it" ), for make our arm to move, we must exert force on it. According the third law of Newton ( "When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body." ) the arm will exert a force on rest of our body. As there is no friction (there is no support), arm will move in a direction and rest of the body will move in the opposite direction. Thus, I think if we move some part of our body, we will be exploded finally.
I think for exerting any contact force, we need a supporting force exerted on us.
I think for exerting any contact force, we need a supporting force exerted on us.
Answered by
0
Hey dear here is the answer
Although friction is not one of the four basic forces of nature, it exists because those basic forces exist. Friction is the resistance to motion of two objects held against each other.
Friction that allows us to walk depends on gravity to convert our mass to weight which holds our feet against the surface where static friction enables the soles of our shoes to push off against the surface of the Earth.
Even when ice skating, kinetic friction keeps the blades sliding against the ice in a forward direction, and static friction allows the skates to push off to propel the skater forward.
Some friction is caused by molecular attraction, such as when Vibram soles are able to maintain grip on smooth rock. This is the result of electromagnetic forces in the rubber molecules of Vibram attracting rock molecules.
Even a rocket engine, which otherwise could be used to propel you in a frictionless environment, depends on the difference in force between friction caused by great pressure of propellant exhaust on a small area (exit pressure) and the lesser friction of propellant exhaust flowing through a larger area (free stream pressure). The equation for rocket thrust shows this:
rocket thrust=mass flow rate×exit velocity+(exit pressure−free stream pressure)×exit area
Hope its help you
Although friction is not one of the four basic forces of nature, it exists because those basic forces exist. Friction is the resistance to motion of two objects held against each other.
Friction that allows us to walk depends on gravity to convert our mass to weight which holds our feet against the surface where static friction enables the soles of our shoes to push off against the surface of the Earth.
Even when ice skating, kinetic friction keeps the blades sliding against the ice in a forward direction, and static friction allows the skates to push off to propel the skater forward.
Some friction is caused by molecular attraction, such as when Vibram soles are able to maintain grip on smooth rock. This is the result of electromagnetic forces in the rubber molecules of Vibram attracting rock molecules.
Even a rocket engine, which otherwise could be used to propel you in a frictionless environment, depends on the difference in force between friction caused by great pressure of propellant exhaust on a small area (exit pressure) and the lesser friction of propellant exhaust flowing through a larger area (free stream pressure). The equation for rocket thrust shows this:
rocket thrust=mass flow rate×exit velocity+(exit pressure−free stream pressure)×exit area
Hope its help you
Similar questions