Ch2 Study Guide
Which potatoes when peeled produce the most peelings?
10 kg of small potatoes
The mass of a cubic meter of water is
1000 kg.
For approximately every 32 ft below the surface of water the pressure increases by about how many lbs/in2?
15
Normal atmospheric pressure in about how many lbs/in2?
15
Do 100 J of work in 50 s and your power output is
2 W.
The pressure at the deepest point of a lake 32 ft deep is about
30 lb/in2
Doubling the linear size of an object multiplies its area by
4 and its volume by 8.
A 120 lb girl stands on one foot. The bottom of her foot has a has an area of 30 in2 . The pressure on the floor (in lb/in2) is
40
A wooden block has a mass of 1000 kg and a volume of 2 cubic meters. What is the block's density?
500 kg per cubic meter
If 50 Newtons of force is added over a liquid with 1 m2 of surface area surface area, how many Newtons of weight can be lifted by a hydraulic piston with a surface area of .01 m2?
5000 N
Which has the most pressure at the bottom?
A tube of water 20 m deep with a diameter of 1 cm.
How far must one travel to get away from the Earth's gravitational field?
Forget it; you can't travel far enough.
Kinetic Energy Formula
KE=1/2mv^2
Pressure Formula
P=F/A
Power Equation
P=W/t
Potential energy equation
PE=mgh
Volume/density/mass calculation
V=M/D
Work equation
W=Fd
For which of the following warm blooded animals is it easiest to maintain body temperature?
a horse.
The Earth's gravitational field extends
both inside and outside the Earth and throughout the entire universe.
The pressure in a liquid depends on liquid
both of these
Water pressure is greatest against the
bottom of a submerged object.
The attraction between molecules of the same kind is called
cohesion.
If the mass of an object were to double while its volume remains the same, its density would
double
A clerk can lift containers a vertical distance of 1 meter or can roll them up a 2 meter-long ramp to the same elevation. With the ramp, the applied force required is about
half as much.
If the mass of the Earth somehow increased with no change in radius, your weight would
increase also.
Compared to a 50-kg person, a 100-kg person at the beach requires
less than twice as much suntan lotion.
An object may have potential energy because of its
location.
Compared to an empty ship, the same ship loaded with Styrofoam will float
lower in the water.
According to Newton, doubling the distance between two interacting objects
makes the gravitational force between them 1/4 as great.
The reason the moon does not crash into the Earth is that the
moon has a sufficient tangential speed to keep it in orbit for a very long time.
An object that has kinetic energy must be
moving.
If you push for a half hour or a whole hour against a stationary wall
no work on the wall is done
Newton discovered
that gravity is universal.
The reason a life jacket helps you float is
the density of both you and the jacket together is less than your density alone.
No work is done by gravity on a bowling ball that rolls along a bowling alley because
the force on the ball is at right angles to the ball's motion.
After rolling halfway down an incline, a marble's kinetic energy is
the same as its potential energy.
If you do work on an object in one-third the usual time, your power output is
three times the usual power output.
An object lifted 10 meters gains 200 J of potential energy. If the same object is lifted 20 meters, its potential energy gain is
twice as much
If you push an object a given distance, while applying twice the force, you do
twice as much work.
When a chocolate bar is cut in half, its density is
unchanged
A completely submerged object always displaces its own
volume of fluid.