 |
 |
Force to Push or Pull
Name: Boyang
Status: student
Grade: 6-8
Location: MI
Country: N/A
Date: 1/9/2005
Question:
Does it take more force to pull a thing up a hill or
push the same thing up a hill?
Replies:
If you are pulling or pushing exactly level to the ground, both ways take
the same force. But usually, one or the other takes less force, because
one way tends to shove the thing you're moving into the ground (making
it harder to move) and the other way tends to lift the thing up. So if
you are moving a sled, for example, it is easier to pull; but if you are
moving
something taller than you, it is usually easier to push.
Tim Mooney
If the force is applied at the same point on the thing and points in the
same direction, it does not matter. In real life, if you are pushing a large
box up a grassy hill so the box may turn over or dig into the grass, it may,
for example, go up easier if you are pulling upward on the box. If the box
is on frictionless wheels, it does not matter whether you push or pull.
To get the box up as easily as possible when it is on wheels, the force
should be in a direction parallel to the slope of the mountain. Any
component of the force directed inward toward the mountain (or upward away
from the mountain) does not help get the box up the mountain.
Best, Dick Plano...
Boyang,
It takes exactly the same force either way. What is much more important is
how you push or pull. When pulling, a person tends to lift a little. This
makes it easier for the box to slide along the ground. When pushing, a
person also tends to push downward on the box. This makes it harder for the
box to slide.
If you have a very heavy box that is small, it can be difficult to get a
good grip on it. Attaching a rope and pulling becomes easier. If the box
is very large, pressing your shoulder against the box works better than
trying to pull a rope. Pushing becomes easier.
Dr. Ken Mellendorf
Physics Instructor
Illinois Central College
Click here to return to the Physics Archives
| |
Update: June 2012
|
|
