According to galelio., he told that a person who is at rest, will remain at rest and a person in motion will remain in motion until some external force is applied. But if a person lying at rest on his bed wants to get up, he can easily do that and he walks off even though no extra external force was applied. How was he able to do so?

Open in App

Solution

When a person lying at rest on his bed tries to get up he excerts a force on the bed using his body muscles.
This force excerted by his body on the bed is an external force and hence his state of rest is disturbed.
Similarly in the case of walking , his legs excerts a mascular force on the ground which helps him to move forward.

So the force excerted by our body is also an external force and helps us to move.

Suggest Corrections

Similar questions

A person was moving at a uniform speed, but suddenly he comes to rest. What will be his acceleration at rest?

An object remains in the state of rest or motion until any external force is applied because of

Newton's first law says that if a body is at rest it remain at rest but if a body is moving in uniform linear motion it keep moving on and on and on untill a external force is applied ,so when I slip my book in straight line it stops after 3 s how this is done which force is stopping my book to keep moving .

Q. 1st law of newton say if a object in rest it remain in rest,if it is in motion it remail in motionj unless untill external force applied on it..they we my chage our state rest to motion it not apply any external force.how

Q. Assertion :An external force is not necessarily required to keep a body in uniform motion. Reason: If the net external force is zero, a body at rest continues to remain at rest and a body in motion countinues to move with a uniform velocity.

Join BYJU'S Learning Program