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Normal body temp is 98.6F. This person's temperature is not too muchhigher.

Problem 1Saturday, June 16, 2012

6:10 PM

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6:10 PM

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There are a couple of ways to do this problem, but this is how I

approach it.

For the aluminum vessel, the interior wall will have its circumference

increase because of the coefficient of linear expansion. Also, the depth

will increase for the same reason. If we used the coefficient ofvolume

expansion for aluminum (~3Al), the capacity of the container will

increase...

The volume of the turpentine also increased in this process. The new

volume of turpentine minus the new volume of the container gives the

volume of turpentine that spills out.

Problem 3Saturday, November 17, 2012

3:44 PM

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Now the turpentine is going to cool...

Because the volume of the container is as it was before (2 L), the

container is 95.2% full. Because the area is the same as it was initially,

the height of the fluid is this same percentage of the initial height. This

means that the height has fallen by...

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This is complicated, but a typical instance of pushing the universal gas

law. First lets find the volume of air that we are talking about.

The new volume is the percentage of this volume. This new volume is

the volume that goes into the universal gas law.

Solving this for pressure...

To calculate the pressure, remember that our temperatures must be

expressed in kelvin and our atmospheric pressure is 1.013x105 Pa.

Doing the calculation...


3:44 PM

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Now, the amount of material in the tire remains fixed. This gives a

relationship between pressure, volume and temperature.

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Problem 5Wednesday, June 20, 2012

9:44 AM

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First, the bullet must be cooled to the temperature of the ice. This takes

energy out of the ice.

The kinetic energy of the bullet is also converted to heat. This heat will

melt more ice.

This mechanical and thermal energy will convert ice to water.


3:44 PM

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The work don on the gas by us if found by the expression...

Using this expression, we see that

Notice that is not given in SI units so you will have to convert,

knowing that...

Problem 7Saturda y, November 17, 2012

3:44 PM

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Problem 8Friday, May 18, 2012

9:10 AM

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If the student is the origin of the coordinate system, and the

student is holding the stone, then the stone is at the origin.

Because the stone is initially thrown to the right, it only has an x

component.

The vertical problem has a constant acceleration from gravity.

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Because the stone is in freefall motion, gravity is the only

acceleration in the problem. There is no acceleration in the x

direction so it has a constant speed in the x direction.

Because there is no acceleration in the x direction, the final x

velocity is the same as the initial.

We can use KE (1) to find the velocity in the y direction with

time.

For the x coordinate, let's use KE (3)

We can also use KE (3) for the vertical component.

We know that the stone hits the water when yf = -h.

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We can find the vertical component of velocity after this

time.

The horizontal component of velocity doesn't change.

The total velocity is then

The angle can be found trigonometrically from the

components of velocity.

Because of the way this angle is measured, WebAssign is looking for

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This is the same kind of problem we did this time on the elevator.

Ferrari

BMW

Because the cars are tied together, the acceleration must be the same

for each.

Problem 9Saturday, May 19, 2012

9:04 AM

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Here we only need to know the height of the block with respect to

point (B). This is the radius of the bowl.

The potential energy at (A) is converted entirely to kinetic energy at (B).

Knowing the kinetic energy at point (B), we can calculate the speed.


3:44 PM

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At point (C), there is a mixture of potential and kinetic energy. The

potential is related to the height relative to point (B). The kinetic energy

at point (C) is...

Obviously the potential energy at point (C) is...

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This is a complicated problem, but it is excellent practice in keeping

parts of collisions straight in your mind. First, for block m1, we are

converting potential energy to kinetic energy.

When m1 gets to the bottom of the ramp, there is a perfectly elastic

collision with m2. After the collision, m1 will have a final velocity v1f.

Now this kinetic energy that block 1 has after the collision will be

Problem 11Friday, June 01, 2012

5:50 PM

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converted back to potential energy.

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I would like to handle this object as one big object. For this, I will need

to know the center of mass (in order to get potential energy) and the

moment of inertia about the end (to get the correct kinetic energy

terms).

The center of mass for this object (from the pivot) is...

The moment of inertia is found in parts. The moment of


8:15 PM

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inertia for the rod part is

The moment of inertia for the ball can be found by the parallel-axis

theorem.

Running the numbers, the final moment of inertia is...

Now we can convert potential energy to kinetic energy.

Because we have the moment of inertia, we can convert this expression

for energy into angular velocity.

It would have been more interesting to find the speed of the center of

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mass of the whole arm, but they took the easy way out. The center of

mass for the ball is at...

The speed at this point is...

If the ball had just fallen freely, its velocity would have been...

The swing is then faster by...

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This is a Kepler 3 problem. We know the relation...

Solving for the mass of Jupiter...


5:07 PM

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