Physics Midterm

One year is about ____ seconds while one day is exactly ____ seconds.

3.16 ´ 10^7, 86 400

A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/hr in 8.00 s. If so, what is the acceleration? (Hint: First convert speed to m/s.)

3.47 m/s^2

A rock is thrown straight up with an initial velocity of 24.5 m/s. What maximum height will the rock reach before starting to fall downward? (Take acceleration due to gravity as 9.80 m/s2.)

30.6 m

A high fountain of water is in the center of a circular pool of water. You walk the circumference of the pool and measure it to be 150 meters. You then stand at the edge of the pool and use a protractor to gauge the angle of elevation of the top of the fountain. It is 55°. How high is the fountain?

34 m

Calculate (0.82 + 0.042) ´ (4.4 ´ 10^3), keeping only significant figures.

3800

When NASA was communicating with astronauts on the moon, the time from sending on the Earth to receiving on the moon was 1.28 s. Find the distance from Earth to the moon. (The speed of radio waves is 3.00 ´ 108 m/s.)`

384000

Mt. Everest is more than 8 000 m high. How fast would an object be moving if it could free fall to sea level after being released from an 8000-m elevation? (Ignore air resistance.)

396 m/s

The length and width of a standard sheet of paper is measured, and then the area is found by calculation to be 93.50 in2. The number of significant figures in the width measurement must be at least:

4

Maria throws two stones from the top edge of a building with a speed of 20 m/s. She throws one straight down and the other straight up. The first one hits the street in a time t1. How much later is it before the second stone hits?

4 seconds

A circle has an area of 2.0 m2. A second circle has double the radius of the first. The area of the second circle is ____ times that of the first.

4.0

A rock is thrown straight up with an initial velocity of 19.6 m/s. What time interval elapses between the rock's being thrown and its return to the original launch point? (Acceleration due to gravity is 9.80 m/s2.)

4.00 s

A truck moves 70 m east, then moves 120 m west, and finally moves east again a distance of 90 m. If east is chosen as the positive direction, what is the truck's resultant displacement?

40 m

Omar throws a rock down with speed 12 m/s from the top of a tower. The rock hits the ground after 2.0 s. What is the height of the tower? (air resistance is negligible)

44 m

The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 30 cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 2.0 ´ 10-5 m. Find the total surface area of these N spherical droplets.

45 000 cm^2

A rock is thrown straight down with an initial velocity of 14.5 m/s from a cliff. What is the rock's displacement after 2.0 s? (Acceleration due to gravity is 9.80 m/s2.)

49 m

A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the final velocity after 11 s?

5.1 m/s

On planet Z, the standard unit of length is the foose. Ann the Astronaut is 5.90 feet tall on earth. She lands on planet Z and is measured to be 94 foosi tall. Her partner Rachael is 88 foosi tall. How tall is Rachael on Earth?

5.5 feet

A basketball player can jump 1.6 m off the hardwood floor. With what upward velocity did he leave the floor?

5.6 m/s

On planet Q the standard unit of volume is called the guppy. Space travelers from Earth have determined that one liter = 38.2 guppies. How many guppies are in 150 liters?

5730 guppies

A water rocket, launched from the ground, rises vertically with acceleration of 30 m/s2 for1.0 s when it runs out of "fuel." Disregarding air resistance, how high will the rocket rise?

61 m

Water flows into a swimming pool at the rate of 8.0 gal/min. The pool is 16 ft wide, 32 ft long and 8.0 ft deep. How long does it take to fill? (1 U.S. gallon = 231 cubic inches)

64 hours

A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.0 m/s2. What is the magnitude of the cart's displacement during the first 6.0 s of its motion?

66 m

Doubling the radius of a sphere results in increasing its volume by a factor of

8

A train slowly climbs a 500-m mountain track which is at an angle of 10.0° with respect to the horizontal. How much altitude does it gain?

86.8 m

A drag racer starts from rest and accelerates at 10 m/s2 for the entire distance of 400 m (1/4 mile). What is the velocity of the race car at the end of the run?

89 m/s

A cement truck can pour 20 cubic yards of cement per hour. Express this in ft3/min.

9 ft^3/min

A parachutist jumps out of an airplane and accelerates with gravity to a maximum velocity of 58.8 m/s in 6.00 seconds. She then pulls the parachute cord and after a 4.00-second constant deceleration, descends at 10.0 m/s for 60.0 seconds, reaching the ground. From what height did the parachutist jump?

914 m

Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 12.4 + 11 + 67.37 + 4.201?

95

Which point is nearest the x axis?

(5, -2)

An object moves 20 m east in 30 s and then returns to its starting point taking an additional 50 s. If west is chosen as the positive direction, what is the sign associated with the average velocity of the object?

0 (no sign)

The information on a one-gallon paint can is that the coverage, when properly applied, is 450 ft2. One gallon is 231 in3. What is the average thickness of the paint in such an application?

0.003 6 in

A cereal box has the dimensions of 0.19 m ´ 0.28 m ´ 0.070 m. If there are 3.28 feet per meter, then what is the volume of the box in cubic feet?

0.13 cubic feet

A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is its acceleration?

0.46 m/s^2

An object moves 20 m east in 30 s and then returns to its starting point taking an additional 50 s. If west is chosen as the positive direction, what is the average speed of the object?

0.50 m/s

If j = 90o - q, what is the value of sin2 j + sin2 q?

1

The mass of the sun is 2.0 ´ 1030 kg, and the mass of a hydrogen atom is 1.67 ´ 10-27 kg. If we assume that the sun is mostly composed of hydrogen, how many atoms are there in the sun?

1.2 ´ 10^57 atoms

Assume everyone in the United States consumes one soft drink in an aluminum can every two days. If there are 270 million Americans, how many tons of aluminum need to be recycled each year if each can weighs 1/16 pound and one ton = 2000 pounds?

1.5 Million Tons

At the top of a cliff 100 m high, Raoul throws a rock upward with velocity 15.0 m/s. How much later should he drop a second rock from rest so both rocks arrive simultaneously at the bottom of the cliff?

1.78 seconds

A baseball is released at rest from the top of the Washington Monument. It hits the ground after falling for 6.0 s. What was the height from which the ball was dropped? (g = 9.8 m/s2 and assume air resistance is negligible)

1.8 ` 10^2

If point A is located at coordinates (5, 3) and point B is located at coordinates (-3, 9), what is the distance from A to B if the units of the coordinated system are meters?

10 m

A vehicle designed to operate on a drag strip accelerates from zero to 30 m/s while undergoing a straight line path displacement of 45 m. What is the vehicle's acceleration if its value may be assumed to be constant?

10 m/s^2

The prefixes which are abbreviated p, n, and G represent which of the following?

10^-12, 10^-9, and 10^9

A physics class in a large lecture hall has 150 students. The total mass of the students is about ____ kg.

10^4

An apartment has 1100 ft2 of floor space. What is the approximate volume of the apartment?

10^4 ft^3

The ratio M/m of the prefixes M and m has what value?

10^9

A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 8.00 s. What distance will the sports car travel during the 8 s acceleration period? (Hint: First convert speed to m/s.)

111 m

Norma releases a bowling ball from rest; it rolls down a ramp with constant acceleration. After half a second it has traveled 0.75 m. How far has it traveled after two seconds?

12 m

A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey?

12.6 s

A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball during this time interval?

13400 m/s

A rock, released at rest from the top of a tower, hits the ground after 1.5 s. What is the speed of the rock as it hits the ground? (g = 9.8 m/s2 and air resistance is negligible)

15 m/s

An automobile driver puts on the brakes and decelerates from 30.0 m/s to zero in 10.0 s. What distance does the car travel?

150 m

A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What minimum distance must a gazelle running 80.0 km/hr be ahead of the cheetah to escape?

167 m

A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6 m/s2. The ball reaches the bottom of the hill in 8.0 s. What is the ball's velocity at the bottom of the hill?

17 m/s

Each edge of a cube has a length of 25.4 cm. What is the length of a diagonal of the cube going through the center of the cube?

17.3

A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 8.00 s. What is the speed after the first 5.00 s of acceleration? (Hint: First convert the speed to m/s.)

17.4 m/s

The distance of the Earth from the sun is 93 000 000 miles. If there are 3.15 ´ 10^7 s in one year, find the speed of the Earth in its orbit about the sun.

18.6 miles/s

A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average speed is:

19.6

Multiplying a 2 significant figure number by a 3 significant figure number and then dividing the product by a six significant figure number yields a number with how many significant figures?

2

The number 0.00017 has how many significant figures?

2

The distance to the Andromeda Galaxy is estimated at about 2 ´ 106 light years. A light year is the distance traveled by light in one year; if the speed of light is 3 ´ 108m/s, about how far is it from our galaxy to Andromeda? (1 year = 3.15 ´ 107 s)

2 ´ 10^22 m

A Cessna aircraft has a lift-off speed of 120 km/hr. What minimum constant acceleration does this require if the aircraft is to be airborne after a take-off run of 240 m?

2.31 m/s^2

Modern electroplaters can cover a surface area of 60.0 m2 with one troy ounce of gold (volume = 1.611 cm3). What is the thickness of the electroplated gold?

2.68 ´ 10^-8 m

Human reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? The nearest value is:

20 cm

A right triangle has sides 5.0 m, 12 m, and 13 m. The smallest angle of this triangle is nearest:

23 degrees

A triangle has sides of length 7.0 cm and 25 cm. If the triangle is a right triangle, which of the following could be the length of the third side?

24 cm

When a drag strip vehicle reaches a velocity of 60 m/s, it begins a negative acceleration by releasing a drag chute and applying its brakes. While reducing its velocity back to zero, its acceleration along a straight line path is a constant -7.5 m/s2. What displacement does it undergo during this deceleration period?

240 m

A furlong is a distance of 220 yards. A fortnight is a time period of two weeks. A race horse is running at a speed of 5.00 yards per second. What is his speed in furlongs per fortnight?

27,500 furlongs/fortnight

Gwen releases a rock at rest from the top of a 40-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the speed of the rock as it hits the ground?

28 m/s

John throws a rock down with speed 14 m/s from the top of a 30-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the rock's speed just as it hits the ground?

28 m/s

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 10.5 x 8.8 x 3.14?

290

Two objects of different mass are released simultaneously from the top of a 20-m tower and fall to the ground. If air resistance is negligible, which statement best applies?

Both objects hit the ground together.

In one-dimensional motion where the direction is indicated by a plus or minus sign, the average velocity of an object has which of the following properties?

It is positive, negative, zero

An object is dropped from a height. Once it is moving, which of the following statements is true, at least at one point?

Its velocity is never equal to its acceleration

Suppose an equation relating position, x, to time, t, is given by x = b t3 + c t4, where b and c are constants. The dimensions of b and c are respectively:

L/T^3, L/T^4.

Areas always have dimensions ____ while volumes always have dimensions ____.

L^2, L^3

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time)

at

A baseball catcher throws a ball vertically upward and catches it in the same spot when it returns to his mitt. At what point in the ball's path does it experience zero velocity and non-zero acceleration at the same time?

at the top of its trajectory

On a position versus time graph, the slope of the straight line joining two points on the plotted curve that are separated in time by the interval Dt, is which of the following quantities?

average velocity

In the case of constant acceleration, the average velocity equals the instantaneous velocity:

half-way through the time interval.

Note the expression: y = x2. Which statement is most consistent with this expression?

if x doubles, then y quadruples

Note the expression: y = A/x3. Which statement is most consistent with this expression?

if x is halved, y is multiplied by 8

When was the existence of the neutron confirmed?

in 1932

In mechanics, physicists use three basic quantities to derive additional quantities. Mass is one of the three quantities. What are the other two?

length and time

The speed of a boat is often given in knots. If a speed of 5 knots were expressed in the SI system of units, the units would be:

m/s.

A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average velocity is:

not given

If the displacement of an object is given in SI units by Dx = -3 t + 4 t 2, at t = 2 s its velocity and acceleration are, respectively:

positive, positive

The nuclei of atoms contain:

protons and neutrons

Changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities?

speed

Which of the following is not a vector quantity?

temperature

A strobe photograph of a car moving along a straight road shows the interval between each successive image to be diminishing. If the direction of motion of the car is taken as positive, which of the following are negative?

the average acceleration of the car

An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the velocity of the ball is zero. We can be positive that at t = 5 s,

the ball has stopped

The slope of the acceleration vs. time curve represents:

the rate of change of acceleration.

A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s,

the velocity of the ball is not changing

If the displacement of an object, x, is related to velocity, v, according to the relation x= Av, the constant, A, has the dimension of which of the following?

time

The proton contains which of the following combination of quarks?

two up quarks and one down quark

Which expression is dimensionally consistent with an expression that would yield a value for time-1?(v is velocity, x is distance, and t is time)

v/x

If a is acceleration, v is velocity, x is position, and t is time, then which equation is not dimensionally correct?

v=a/t

Displacement is which of the following types of quantities?

vector

For which of the values below is x > x3?

x = -1.5

Jeff throws a ball straight up. For which situation is the vertical velocity zero?

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