PHY 110 Test #1

Let us say m and n are known. What combination of experiments would be considered a minimum set for determining p and k?

A 1 and 2

If the force exerted by the piston is F2, what load can be lifted?

A. (a1/a2)*f2

Which expression most nearly gives the force his muscles must exert to push out his chest?

A. (gauge pressure of the water)x(area of his chest)

A silver necklace has a mass of 50 grams and a volume 4.82 cm^3. It is tied to a string and lowered into a glass of water. The other end of the string is connected to a force meter. What is the reading on the force meter?

A. .44 N

In two trials, two masses are attached to a spring and he periods recorded. Mass P resulted in a period 36 times larger than the period of mass Q. What can be concluded?

A. 1296 larger

In a certain assay, a number of microbes is measured by determining the mass of the sample. It is known that the average mass of a microbe (of this species) is 6.0x10^-16 g. How many microbes are in a sample of mass 1.1x10^-12 g?

A. 1800

What is the gauge pressure 5 meters below the surface of the ocean?

A. 5x10^4 Pa

What does the force meter read?

A. 6.9 N

How could the maximum height be increased in Model 2?

A. Decrease the radius of the cylinder

Why is it difficult for the man to breathe?

A. His lungs are expanding against a net 10^4 Pa of pressure.

The liquid in the tube is water, with the density of p=1.0g/cm^3. The height of water in the reservoir column is h1. The height of water in the open column is h2. What would happen to the height difference h2-h1 if the water were replaced by salt water with the density 1.2 g/cm^3?

A. It would decrease

Which pressure is greater, the pressure at p1 or at p2?

A. Pressure at p1 is greater than at p2 by the term pgh.

A wire circle is sitting on the surface of the water, and a solid circle of the same diameter is also sitting on the water. Which one can have the larger maximum mass without sinking?

A. The wire circle, by a factor of 2

Which graph best show the relationship between the potential V and the electric field E?

A. Upward Sloping from 0,0

If the piston and the load are at the same height, and the pressure of the fluid near the piston is p2, what is the pressure of the fluid near the load?

A. p2

If Julie increases her speed from 30 mph to 60 mph, how does the energy required to travel from Tucson to Phoenix change?

B Factor of 4

An object floats with one tenth of its volume of the water. What is its specific gravity?

B. .9

What is maximum height of a column of water in xylem in Model 1?

B. 10 meters

If a mass of 60 g is connected to a certain spring, the frequency is 30 Hz. If a mass of 240 g is connected to the same spring, what is the frequency?

B. 15 Hz

Which pair of experiment indicates that retarding force does not depend on the density of the object?

B. 2 and 3

Which pair of experiments could be used to determine n?

B. 3 and 4

A certain substance has a density 8.4 ug/mL. What is the mass of 422.4 mL?

B. 3.55

The length of the rod of a certain pendulum is decreased, and the period then decreases by 20%. By how much was the rod length decreased?

B. 36%

Scott drives a very large 50s style car, and Laura drives a small 90s style car, so that every linear dimension of Scotts car is double that Laura's car. On the basis of energy loss due to air resistance alone, how much more energy would you expect Scott's car to expend getting from Tucson to Phoenix than Laura's car?

B. 4 times as much energy

A thread in the shape of a rectangle is lying on the surface of the water. If y is the surface tension of then what is the maximum weight that the thread can have without sinking?

B. 4y(l+w)

Two liters of argon gas are at 10 atm of pressure. If the sample is 16 g, what is the temperature?

B. 610K

In a given experiment, all other things being held constant, what happens to the force on a proton between the plates if the separation of the plates is increased by a factor of 2.

B. Decreases Factor of 2

If the voltage in a given experiment is held constant, but the distance between the plates is increased by a factor of 3, how is the electric field affected?

B. Decreases Factor of 3

How does the volume of square pyramid change if the height is increased by a factor of 12 and the base side length is unchanged?

B. Factor of 12

If the length of the string of a pendulum is increased by a factor of 4, how does the period change?

B. Factor of 2

If a pendulum is transported to the Moon, where the acceleration due to gravity is six times less than that here on Earth how would the period of the pendulum change?

B. Factor of 2.4

If the volume of a sphere decreases by a factor of 27, what happens to its diameter?

B. Factor of 3

If the diameter of a circle is increased by a factor of 4, what happens to the circumference?

B. Factor of 4

Which option will help a customer to draw the beverage up the straw?

B. II only

In a certain experiment two balls are both given a charge q, they are set a distance r away from each other, and the force between them is recorded. Which graph best represents the relationship between F and q?

B. Sloping upward, u shaped

An arrow is shot into the air. When the arrow is in the air what forces are acting on the arrow?

B. There is the force of gravity

In a given experiment, both a proton and a bare helium nucleus are between plates. How does the force on the helium nucleus compare to the force on the proton?

B. Twice as great

In an experiment, the distance separating the ball is increased by 25%. How does this affect the force between the balls?

B. decreases by 36%

Both flasks contain mercury to a height h. The volume of mercury in the second flask is three times the volume of mercury in the first flask. The area at the bottom of the second flask is twice that of the first flask. Pressure p1 is the pressure at the bottom of the first flask, and p2 is the pressure at the bottom of the second flask. Which equation holds?

B. p2=p1

What happens if r decreases by a factor of 2?

B. the height h would increase by a factor of 2.

If the work done by the piston on the fluid is w2, and the work done by the fluid on the load is w1, which is correct?

B. w1 is equal to w2

A cork floats with three quarters of its volume in and one quarter of its volume out of the water. What is the specific gravity of the cork?

C. .75

A 70 kg man would weigh mg= 70kg*9.8m/s^2=686 N if there were no air. How much weight does the buoyancy due to air take off the man's weight?

C. .8 N

An electrical resistor is installed in a container of water to heat it. The resistor dissipates heat at a rate of 2.0 W, and the container holds 10 kg of water. How long would it take to raise the temperature of the water 5 C?

C. 1.05x10^5

A metal box in the shape of a cube which is .1 m on a side floats in space, where there is a vacuum. the box has 8 grams of oxygen gas in it at 2 atm. Use R = .0821 L atm/K mol, and 1 atm = 1.01x10^5 Pa. What is the best estimate of the force the gas exerts on one face of the cube?

C. 2100 N

Julie modifies her car, so that the effective cross-sectional area is reduced by 20%. How much further can she drive and still use the same amount of energy?

C. 25% Further

What expression approximates the force due to surface tension?

C. 2pi*r*y

What is the mass of a water molecule?

C. 3.0x10^-23 g.

A typical human head has the approximate shape of a cylinder of diameter of .2 meters and height .3 meters. If the pressure of the atmosphere is 1.01x10^5 N/m^2, Fatm be the force acting down on a human head due to the atmosphere. How many kilograms taken together would weigh Fatm?

C. 320

Julie usually drives at a certain speed. How much more energy will she use if she drives 20% faster?

C. 44% more energy

What does the scale holding the water read?

C. 51 N

What is maximum height of a column of water in xylem in Model 2?

C. 72 meters

If the period increases by 50%, how does the frequency change?

C. Decrease 33%

What expression gives the magnitude of the force due to pressure on the top of the column?

C. F=pir^2*patm

If the radius of a circle increases by a factor of 4, what happens to its area?

C. Factor of 16

If every linear dimension of a square pyramid were increased by a factor of 3, how would the volume change?

C. Factor of 27

If a new battery is installed, so that the voltage between the plates is increased by a factor of 9, how is the electric field affected?

C. Factor of 9

What expression gives the force due to gravity on the column?

C. Fgrav=pir^2*hpg

What are the forces acting on the column?

C. Gravity, down; force due to pressure on top surface; force due to pressure on bottom surface; and surface tension, up

A car's engine has died, and the car is slowing down as it coasts. What forces are acting on the car?

C. Gravity, down; the road's force, up; and friction, backwards

If the force between the balls stays the same, but the charge q2 is multiplied by 4, which is a possibility?

C. Increased Factor of 2

If the radius of a circle is increased by 30%, how does the area change?

C. Increases by 69%

To what volume should the balloon be filled to achieve neutral buoyancy?

C. M/2pair(1-phe/pair)

Which graph best shows the relationship between the force between two balls F and their separation r?

C. Sloping downward, u shaped

What happens when the chemist connects her pump to the straw?

C. The beverage will not rise past a certain point, now matter how good the pump is

A car's engine has died, and the car is slowing down as it coasts. What may we conclude about the forces acting on the car?

C. The net force acting on the car is not zero.

An object is moving with uniform motion, that is, at constant speed in a straight line. There are two forces acting on the object. What can we definitely conclude from this?

C. The two forces have equal magnitudes but point in opposite directions

What is the pressure 5 meters below the surface of the ocean?

D. 1.5x10^5 Pa

What is the approximate value of p?

D. 2

Which expression is an approximation for the density of helium in g/cm^3?

D. 4/(.0821)(300)(1000)

In a hypothetical situation, two balls of positive charge exert a force 12 N on each other. The charge on ball A is 2 C. If the charge on ball A is increased to 8 C, and all else is unchanged, what would the force be?

D. 48 N

If the radius of a sphere increases by a factor of 4, what happens to its volume?

D. Factor of 64

How does the volume of a square pyramid change if the base side length is increased by a factor of 9 and the height is unchanged?

D. Factor of 81

In a certain experiment, the separation between the balls is halved, while the charges on the balls are undisturbed. How would this affect the force between them?

D. Increase Factor of 4

How could the maximum height be increased in Model 1?

D. None of the above will increase the maximum height

There is one force acting on an object. What can we definitely conclude from this?

D. Nothing can be concluded

A coffee cup sits fully submerged at the bottom of the sink filled with water. The coffee cup is 120 grams and is able to hold .1 liters of coffee. If the density of water is 10^3 kg/m^3, what is the force that the sink exerts on the coffee cup?

D. There is not enough information to answer the question

Consider a paratrooper who has jumped from an airplane. After an initial accelerating plunge, he begins to fall at a constant speed in a straight vertical plunge (at terminal velocity). During the latter portion of his fall, are the forces on the paratrooper balanced?

D. Yes, since he is moving at a constant velocity

What is the best expression for the pressure in volume 1?

D. patm-phgg(h1-h2)

Iron has a density of Pfe = 7.9 g/cm^3, and mercury has a density phg= 13.6 g/cm^3. A piece of iron is placed in a pool of mercury. Which expression gives the ratio of volume of iron above the surface to volume below the surface of the liquid?

D. phg/pge-1

How does Julie's energy usage change if she changes from driving 50 mph to 55 mph?

It increases by 21%