1) A moving electron particle has kinetic energy K. After a net amount of work W has been done on it, the electron is moving one-quarter as fast in the opposite direction. Find W in terms of K. Does your answer depend on the final direction of the electron’s motion?
i. This is tricky because surely going from a velocity of v to -¼v should be the same as going from v + ¼v to zero. Is it?
ii. Is going from v to -¼v the same as going from v to ¼v? The starting and finishing kinetic energies are the same, but why would the work required to change be different?
2) A pick-up truck is coasting at a speed vA along a straight and level road. When a load equivalent to 10% of the truck’s mass is thrown off the bed, parallel to the ground and in the forward direction, the truck is brought to a halt. If the direction in which this mass is thrown is exactly reversed, but the speed of this mass relative to the truck remains the same, the wagon accelerates to a new speed vB. Calculate the ratio vB/vA.
i. This problem has some deliberate wording. “coasting” implies that the engine is not providing force, and “straight and level road” implies that we can ignore external forces such as gravity. Therefore, all we have to worry about is momentum conservation. Balance the momentum when the truck is moving with the load in its bed to when the truck has come to a stop and the load is thrown forward. What is the velocity of this load, relative to the trucks initial velocity?
ii. Now solve for when the load is thrown backwards, propelling the truck further forwards. Balance the momentum before and after the mass is thrown and find the new velocity of the truck. The mass of the truck should cancel and you should be able to solve for the ratio vB/vA.
3) A kid on a sled, with a combined mass of 35 kg, is pulled up a slope at constant speed by a tow rope that is parallel to the ground. The ground slopes upwards at a constant angle of 26o above the horizontal and the friction between the sled and the ground is characterized by the coefficient of kinetic friction,
. Draw a clearly labeled free-body diagram for the kid on a sled. Calculate the tension in the tow rope.
i. The question asks you to draw a FBD – which is good as this is exactly where you should start to solve this problem! What are the forces acting on the sled?
ii. The question states that the kid on the sled are pulled “at constant speed” which means the acceleration and net force are both zero. Recall, that for problems with slopes you resolve the forces parallel and perpendicular to the slope (usually the force that needs splitting up is the weight, mg). All the forces (which recall are vectors) when added together equals zero. In other words, forces up the hill are equal to forces down the hill, and forces in to the hill and equal to forces out of the hill. This being the case, find the tension in the rope.

1) An American football player, starting from rest at the line of scrimmage, accelerates along a straight line for a time of 1.25 s. Then, during a negligible amount of time, he changes the magnitude of his acceleration to a value of 1.2 m s-2. With this acceleration, he continues in the same direction for another 1.2 s, until he reaches a speed of 3.7 m s-1. What is the value of his acceleration (assumed to be constant) during the initial 1.25 s period?
i. Sketch a plot of velocity versus time.
ii. To solve this problem, you have to work backwards. If the final speed is 3.7 m s-1after accelerating at 1.2 m s-2 for 1.2 s, then what velocity did he have before this 1.2 s burst of acceleration?
iii. It took the player 1.25 s to reach this velocity, accelerating from rest. What was the initial acceleration?
2) Two students are canoeing on a river. While heading upstream, they accidentally drop an empty bottle overboard. They then continue paddling for 1 hour, reaching a point 2 km farther upstream. At this point they realize that the bottle is missing and, driven by ecological awareness, they turn around and head downstream. They catch up with and retrieve the bottle (which has been moving along with the current) 5 km downstream from the turn-around point. Assuming a constant paddling effort throughout, how fast is the river flowing? What would the canoe speed in a still lake be for the same paddling effort?
The unknown variables in this problem seem to be the speed of the river, the speed of the canoe relative to the river and the time it takes from when they turn around to when they retrieve the bottle. 3 unknowns.
i. Write down an equation in terms of the 3 unknowns for the students canoeing upstream. This is of the form, velocity is equal to distance over time.
ii. Write down a similar equation in terms of the 3 unknowns for the students canoeing down stream to retrieve the bottle.
iii. Write down a similar equation in terms of the 3 unknowns for the journey of the bottle from when it was first dropped to when it was retrieved.
iv. You now have 3 equations and 3 unknowns. Do the algebra and solve the problem.
3) The mass of an ant is 5.5×10-6 kg. What is this in grams (g), milligrams (mg) and micrograms ( g)? A dose of a given antibiotic for an infant is one micro-liter per hour (1 l h-1). What is this in meters cubed per second (m3 s-1) and liters per year (l year-1)?
To change units simply multiply by a conversion factor. For example, to convert 2.6 cm to m would be
where the fraction is the conversion. Note 100 cm is equivalent to 1 m, so multiplying the 2.6 cm by this fraction doesn’t change the quantity just the units.

What is the SI unit for density?
The density of blood is 1.05 kg/m3, find the mass of a bag of blood for a transfusion, if the volume is 2.0 m3.
The density of oxygen is 1.43 x 10 -3 kg/m3. If a canister of oxygen has a mass of 0.2 kg, find the volume.
Using the bone density of 2.0 kg/m3, calculate the mass of an adult femur bone that has a volume of 0.00027 m3.
What does psi stand for in units dealing with pressure?
What are the typical units for measuring blood pressure?
Find the pressure if a force of 2 N is applied to an area of 0.0004 m2.
Chapter 13
What is the freezing point of water in K, oF, and oC?
What is the boiling point of water in K, oF, and oC?
Convert 45 oC to Fahrenheit.
Convert 92 o F to Celsius.
Convert 35 oC to Kelvin.
Convert 87 o F to Kelvin.
Convert 200 K to Celsius.
Calculate the change in length on a copper (Coefficient of linear expansion for copper is 17 * 10-6 / oC) rod that is 25 meters that undergoes a temperature change of 15 o
Calculate the change in length of a concrete sidewalk (Coefficient of linear expansion for concrete is 12 * 10-6/ oC) that is 150 meters that undergoes a temperature change of 30 o
Calculate the change in length of a Pyrex glass dish (Coefficient of linear expansion for Pyrex is 3 * 10-6 /oC) that is 0.3 meters that undergoes a temperature change of 250 o
PV=NkT is what law?
Define mole and Avogadro’s number.
Chapter 14
Food calories are actually considered what?
Define heat.
How many Joules is equivalent to a kilocalorie?
Describe and give an example of conduction in the medical field.
Describe and give an example of convection in the medical field.
Describe and give an example of radiation in the medical field.
Writing Assignment worth 45 points. APA style with 400 words or more with at least 1 reference
Density can be calculated by taking the mass of an object and dividing by the volume. How can we apply density to the Medical profession? Let’s look at bone density. Bone density is found by using a certain type of x-ray machine. It is calculated a bit differently and Cleveland Clinic has a brief article describing this test. Discuss an application of density in the Medical profession.