block sliding down incline
If we let the block slide down the incline plane, from a height of 5m. How fast will it be
going by the time it reaches the bottom?
The forces acting on the crate are shown below:
Applying N2L to get the acceleration, we get:
Eq
A more realistic description of free-fall
As briefly mentioned before, there are actually two forces acting on a particle when it is
going through the air one is gravity, and the other is air resistance. Consider a falling
ball,
As an object falls faster
Inclined plane with friction
Consider two masses attached to an inclined. Suppose m1 = 10kg, and m2 = 20kg, and
that the plane is inclined 30 degrees. And suppose that k = 0.4. If we pull down on
block 1 and then let go, what will be its acceleration?
To
Gravity and other forces
Weve now done projectile motion in some detail. At this point well investigate some
more situations, where other forces are acting on the person, object, besides just gravity.
Well analyze forces exerted by people, ropes, and also
Projectile Motion
Now that weve covered the basics of Newtons 3 laws, lets apply them to free
fall/projectile motion. Such motion occurs, as the name suggests, when the object is
flying through the air, subject only to the force of gravity. In order to us
Position as a function of time
If we want the position as a function of time, then we must integrate once more. Using
the fact that the derivative of cosh(x) is sinh(x) (you can verify this to be true from the
definitions above), this comes out to be,
So,
Chandelier problem
Suppose a chandelier is connected to a wall via pulleys. The chandelier has a mass of
100kg, and Russel Crowe has a mass of 80kg. If he cuts the cord holding the chandelier
to the wall, the chandelier will fall, raising him up in the pr
Example: Firing a missile
Consider this example. Were flying an F-22 at an altitude of 1000m and speed 500m/s
on a mission to destroy FSU. We fire a missile at a speed of 300m/s (relative to the
plane). How far away should we be from FSU when we fire the
Example: Static Friction force
Suppose we have a box with mass m = 100kg resting on a surface with coefficient of static
friction s = 0.85. If we exert a force of 500N on it, will it move?
To determine whether it will move or not, we have to see whether F
Example: Falling from the top of a building
Suppose you fall from a 28.5m 90ft. building. And the ground brings you to rest in
about 0.1s. What force does the ground exert on you then? Assume the mass is 70kg.
The solution proceeds in two stages. First we