Workshop 3's Featured Classroom
Armstrong School, Westborough, Massachusetts,
Grade 5,
Teacher: Barbara
Mitchell
Answer to Workshop 3's Getting Ready
"Does Our Weight Change in a Moving Elevator?"
How does your weight change in a moving elevator?
When the elevator is at rest or moving at a constant
speed between floors, the forces are balanced and you will read
your weight, in our example 300 Newtons or about 136 pounds.
As the elevator accelerates upward you can feel an extra force
as the floor of the cab pushes to get you moving. While you
are accelerating, to the constant speed between floors, the
weight you feel and read on the scale is higher, lets say 310
Newtons. As you slow down to a stop you can feel that your body
due to its inertia tends to keep moving, you feel lighter and
the scale reading is less perhaps about 290 Newtons.
These effects you feel are similar to your experiences
in a car as you accelerate, cruise at constant speed or brake
for a stop.
