Why is it that when your in lift and accelerating you feel heavier?

Question

Also why is when you reach a constant speed you feel back to your normal weight. Then when lift starts to deccelerate you feel lighter.

Answer 1

According to Newton's third law of motion, "there is a reaction to every action which is equal in magnitude but opposite in direction".

      This is so because we are going upwards (action) against the force of gravity of the earth (lift) which is pulling us downwards (reaction)...

Answer 2

While accelerating up, there is a net force acting upon you. It is this net force that makes you feel heavier. There is only a net force while accelerating, so a constant speed does not produce a net force, and therefore, does not make you feel lighter or heavier. While decelerating, you feel lighter because the net force is a much smaller value.

Answer 3

Surrounding Air Pressure

Answer 4

gravity my dear Watson

Answer 5

When the lift is going up, it has a powerful mechanisim to push it up and it moves up before you do so you feel the lift pulling you up so you feel heavier.

When it's at a constant speed, you are travelling at the same speed as the lift and no force is needed on you so you don't feel any change.

Whe it decelerates, you are travelling faster than the lift and so the lift doesn't push you up so much as you still have some energy in you lifting you up from when it was going faster. Therefore it feels lighter.

Not the most scientific explanation but it's correct.

Answer 6

Inertia my dear Watson...

Your body is resisting change in its kinetic energy level.  You remember Newton's Laws of Motion... an object at rest will tend to stay at rest and an object in motion will tend to stay in motion, unless acted upon by an outside force.

You step in the lift, your body is at rest.  The lift begins to rise, pushing against your body, changing your body from an object at rest to an object in motion.

When your body is moving at the same speed as the lift, then you no longer feel the push of the lift.  Thus the only net force acting on you at that time is gravity, so you feel like your normal weight.

When the lift slows down, your body in motion attempts to stay in motion, continuing along the path of the lift.  Again gravity acts on you, counteracting the inertia imparted to you by the lift when it accellerated.  Because the inertia is still trying to move you up, while gravity is trying to move you down, for as long as your inertia is not at rest you are "lighter" because the inertia is subtracted from the gravity until you are at rest again.  Then with only gravity acting on you, you are your 'normal' weight again.

In relativistic terms, it is impossible to distinguish between gravity and the force of acceleration.

Hope this helps!

Answer 7

When lift is accelarating upwards with accelaration "a" , it can be taken to be having a downward decelaration "a", thus net force on you equals F= m(g+ a).  which is greater than your weight '"mg".

For accelaration downwards or decelaration upwards net force is F= m(g- a) < mg , making you feel lighter.

For uniform motion i.e. with constant speed F= mg which is your normal weight.

Answer 8

its called positive G force , its the same on a roller-coaster when you are going up , when you are falling on a roller-coaster and you feel lighter that's Negative G force