Final Exam Questions and Answers

A car traveling at 30 m/s comes to a stop after 2 s. What was the car's average acceleration?

-15 m/s^2

A ball traveling at +10 m/s bounces off the wall and returns the way it came with a speed of 10 m/s. What is the change in velocity?

-20 m/s

What is 4.1x10^-5 ns in decimal notation?

0.000041 ns

What is 7.63x10^-5 in decimal notation?

0.0000763

What is 2.829x10^-4 in decimal notation?

0.0002829

A constant horizontal force of 1.2 N is applied tangentially to the shaft of a solid disk rotating about a vertical axis. The radius of the disk is 8 cm, and its mass is 4 kg. Calculate the moment of inertia of the disk. Moment of inertia for a disk=1/2mr^2

0.0128 kg*m^2

927 ft/min^2 = ________ m/s^2

0.0785 m/s^2

What is the result of the following calculations, reported to the correct number of significant figures? 0.12g+0.003g=?

0.1g

A 50 N sled rests on a horizontal surface. A horizontal pull of 10 N is required just to start the sled moving. Find the coefficient of static friction (Us).

0.20

The thickness of the leg of an ant is 0.035 centimeters. How many millimeters is this?

0.35 mm

469.1 mg = _________ g?

0.4691 g

A 45 kg merry-go-round worker stands on the ride's platform 6.3 m from the center. If her speed as she goes around the circle is 4.1 m/s, what is the force necessary to keep her from falling off the platform? (answer in scientific notation)

1.2x10^2 N

Express 15,000,000,000 in scientific notation

1.5x10^10

The acceleration due to gravity on the Moon is 1/6 that on Earth. What is the weight of a 600 N woman on the Moon?

100 N

Two spherical objects have masses of 8.1x10^2 kg and 4.5x10^8 kg. The gravitational attraction between them is 1.9x10^-3 N. How far apart are their centers?

113 m

Jerry knocks a flowerpot off its third story ledge, 9.5 m above the ground. If it falls freely with a constant acceleration, how fast is the flowerpot moving when it crashes to the sidewalk?

14 m/s

A child with a mass of 25 kg is riding on a merry-go-round. If the child has a speed of 3 m/s and is located 2 m from the center of the merry-go-round, what is the child's angular momentum?

150 kg*m^2/s

What is 1.59x10^7 g in decimal notation?

15900000 g

A constant force of 95.3 N, directed upward, is applied to a 3.5 kg toy rocket by the rockets engine. What is the rockets acceleration?

17.4 m/s^2

A woman with a mass of 60 kg climbs a set of stairs that are 3 m high. How much gravitational potential energy does she gain?

1800 J

In correct scientific notation, the number 1/1000 would be...?

1x10^-3

How many significant figures does the following measurement contain? Temperature = 0.0023 degrees C

2

A 2 kg ball traveling to the right with a speed of 3 m/s collides with a 4 kg ball traveling to the left with a speed of 2 m/s. The total momentum of the two balls after the collision is _________ kg*m/s to the _________?

2... left

What is the result of the following calculation to the correct number of significant figures? (2.14x10^4)-(1.11x10^2)=?

2.13x10^4

What is the rotational kinetic energy of an electric motor if the angular velocity is 314.16 rad/s and the moment of inertia is 50 kg*m^2?

2.5x10^6 J

What is 281x10^2 in scientific notation?

2.81x10^4

A crate is acted on by a net force of 100 N and an acceleration of 5.0 m/s^2 results. The mass of the crate is...?

20 kg

A compressed air potato gun, built as a project for a physics class, launches a potato directly upward with a speed of 20 m/s. What maximum height will the potato reach?

20 m

A 1200 kg car traveling north at 14 m/s is rear-ended by a 2000 kg truck traveling at 25 m/s. If the truck and car lock bumpers and stick together, what is their speed immediately after the collision?

20.9 m/s

A box weighing 10 kg is on a shelf 2 m above the ground. What is its potential energy?

200 J

An object has a mass of 20 kg. What is its approximate weight on Earth? (g=10 m/s^2)

200 N

Starting from rest, a car has a constant acceleration of 5.39 rad/s^2. In a time of 7 seconds, how many revolutions does the wheels of the car turn?

21 revolutions

What average power is required to accelerate a 1200 kg car from rest to 20 m/s in 10 s? (answer in watts)

24,000 W

An adult applies a force of 100 N to a merry-go-round perpendicular to its radius. The radius is 2.4 m. What is the net torque on the merry-go-round?

240 N*m

An astronaut on a strange planet has a mass of 80 kg and a weight of 240 N. What is the value of the acceleration due to gravity on this planet?

3 m/s^2

Which of the following has the greatest number of significant figures? A. 3.142 B. 3.1400 C. 0.3140 D. 0.003142 E. 314.1

3.1400

An object is dropped off a cliff. What is its speed 3 s later?

30 m/s

If a sports car with a mass of 1000 kg travels down the road with a speed of 30 m/s, its momentum is...?

30,000 kg*m/s

If you did the appropriate unit conversions, which of the following could be added to the quantity of 4 grams? A. 1 kilometer B. 2 liters C. 5 square meters D. 4 kilograms E. 2 pounds

4 kilograms

You throw a stone horizontally at a speed of 5 m/s from the top of a cliff that is 78.4 m high. How long does it take the stone to reach the bottom of the cliff?

4 s

Two spherical objects have equal masses and experience a gravitational force of 85 N towards one another. Their centers are 36 mm apart. Determine each of their masses.

4.1x10^4 kg

A mass of 4.3x10^3 grams can also be written as...? A. 4.3 megagrams B. 4.3 nanograms C. 4.3 milligrams D. 4.3 kilograms

4.3 kilograms

The measurement 0.0000043 m, expressed correctly using scientific notation, is...?

4.3x10^-6 m

Calculate the distance traveled by a mouse running at 2 m/s for 20 seconds.

40 m

What is 4.37x10^6 in decimal notation?

4370000

In order to go from rest to 100 m/s in 20 s, a jet must be able to accelerate at...?

5 m/s^2

How long does it take for a rotating object to speed up from 15.0 rad/s to 33.3 rad/s if it has a constant angular acceleration of 3.45 rad/s^2?

5.3 s

Two bowling balls, each with a mass of 7.27 kg, are suspended from a ceiling. Find the gravitational force between the two balls if they are suspended 0.250 m from each other.

5.64x10^-8 N

Saturn's moon, Titan, orbits Saturn at a mean distance of 1.22x10^6 km and an orbital period of 15.9 Earth days. Use this data to calculate Saturn's mass.

5.72x10^26 kg

What is 0.00670 m in correct scientific notation?

6.70x10^-3 m

The Galilean moon Europa orbits Jupiter with a period of 3.55 Earth days. Calculate the distance between Europa and Jupiter. M(Jupiter)=1.90x10^27 kg

6.71x10^8 m

A golfer practicing on a range with an elevated tee 4.9 m above the fairway is able to strike a ball so that it leaves the club with a horizontal velocity of 20 m/s. Calculate the vertical velocity of the ball 0.80 s after it leaves the club.

7.84 m/s

A man with a mass of 70 kg falls 10 m. How much kinetic energy does he gain?

7000 J

A cyclist turns a corner with a radius of 50 m at a speed of 20 m/s. What is the magnitude of the cyclists acceleration?

8 m/s^2

An airplane traveling at 201 m/s makes a turn. What is the smallest radius of the circular path the pilot can make and keep the centripetal acceleration at 5.0 m/s^2? (answer in km)

8.1 km

A fully loaded 737 aircraft takes off at 250 km/hr. If its acceleration is a steady 3.0 m/s^2, how long of a runway is required? (answer in m)

803 m

Mercury has the shortest orbital period of any planet in the solar system. Mercury's mean distance from the Sun is 5.79x10^10 m. Calculate Mercury's orbital period. M(sun)=1.99x10^30 kg (answer in days)

88 days

What is the product of 4x10^4 and 2x10^8?

8x10^12

Solve R=(CS)/(d) for C

C=R(d/s)

Solve A=1/2bh for b

b=(2A)/(h)

Solve A=2dr^2+2drh for d

d=(A)/(2r^2+2rh)

Solve 5t-2r=25 for t

t=(25+2r)/(5)

Solve y-y1=m(x-x1) for x

x=(y-y1+mx1)/(m)