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- If I weigh 741 N on Earth at a place where g = 9.80 m/s2 and 5320 N on the surface of another planet, what is the acceleration due to gravity on that planet?

70.4 m/s2 (Fg=mg)

- What is the mass of an object that experiences a gravitational force of 767 N near Earthʹs surface where g = 9.80 m/s2?

78.3 kg (Fg=ma)

- A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown, assuming negligible air resistance?

8.1 m/s (y=VoT+1/2aT2)(x=VxT)

-A jet plane flying 600 m/s experiences an acceleration of 4.0 g when pulling out of a circular dive. What is the radius of curvature of the circular part of the path in which the plane is flying?

9200 m

- Which of the following situations is impossible?

An object has constant non-zero velocity and changing acceleration.

- The figure shows a graph of the position x of two cars, C and D, as a function of time t. According to this graph, which statements about these cars must be true? (There could be more than correct choice.)

Both cars have the same acceleration. , The cars meet at time t = 10 s.

- A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true?

During the collision, the force on the truck is equal to the force on the car.

-A 20-ton truck collides with a 1500-lb car. Which of the following statements must be true?

During the collision, the force on the truck is equal to the force on the car.

- A satellite is in orbit around the earth. Which one feels the greater force? A) the earth because the satellite has so little mass

Earth and the satellite feel exactly the same force.

-A block of mass m sits at rest on a rough inclined ramp that makes an angle θ with the horizontal. What must be true about normal force F on the block due to the ramp?

F = mg cos θ

- Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light.

Its acceleration is in the -x direction.

- A rock is thrown from the upper edge of a tall cliff at some angle above the horizontal. It reaches its highest point and starts falling down. Which of the following statements about the rockʹs motion are true just before it hits the ground? (There could be more than one correct choice.

Its horizontal velocity component is the same as it was just as it was launched.

- A ball is thrown straight up, reaches a maximum height, then falls to its initial height. Which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct?

Its velocity points upward and its acceleration points downward.

-The acceleration due to gravity is lower on the Moon than on Earth. Which one of the following statements is true about the mass and weight of an astronaut on the Moonʹs surface, compared to Earth?

Mass is the same, weight is less.

-A girl attaches a rock to a string, which she then swings counter-clockwise in a horizontal circle. The string breaks at point P in the figure, which shows a birdʹs-eye view (as seen from above). Which path (A-E) will the rock follow?

Path B

- A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct?

The acceleration is downward at all points in the motion.

- Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct?

The acceleration is equal to zero

-Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct?

The acceleration is toward the east.

- Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object.

The displacement is either less than or equal to the distance traveled.

- Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance? (There could be more than one correct choice.)

The horizontal acceleration is always zero and the vertical acceleration is always a non-zero constant downward.

-Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance?

The horizontal acceleration is always zero and the vertical acceleration is always a non-zero constant downward.

- An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

The net force on the object is zero.

-The motions of a car and a truck along a straight road are represented by the velocity -time graphs in the figure. The two vehicles are initially alongside each other at time t = 0. At time T, what is true of the distances traveled by the vehicles since time t = 0?

The truck will have travelled further than the car.

- Brick A is dropped from the top of a building. Brick B is thrown straight down from the same building, and neither one experiences appreciable air resistance. Which statement about their accelerations is correct?

The two bricks have exactly the same acceleration.

- You are standing in a moving bus, facing forward, when you suddenly slide forward as the bus comes to an immediate stop. What force caused you to slide forward?

There is not a force causing you to slide forward.

-In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles.

They hit at the same time

- For general projectile motion with no air resistance, the horizontal component of a projectileʹs acceleration

is always zero.

-When an object moves in uniform circular motion, the direction of its acceleration is

is directed toward the center of its circular path.

-When a ball is thrown straight up with no air resistance, the acceleration at its highest point

is downward

- If a woman weighs 125 lb, her mass expressed in kilograms is x kg, where x is

less than 125.

- You are making a circular turn in your car on a horizontal road when you hit a big patch of ice, causing the force of friction between the tires and the road to become zero. While the car is on the ice, it

moves along a straight-line path in its original direction.

- A car goes around a circular curve on a horizontal road at constant speed. What is the direction of the friction force on the car due to the road?

perpendicular to the curve inward

-Inertia can be best described as the

property responsible for an objectʹs resistance to changes in motion.

For general projectile motion with no air resistance, the horizontal component of a projectileʹs velocity

remains a non-zero constant

- For general projectile motion with no air resistance, the vertical component of a projectileʹs acceleration

remains a non-zero constant.

-You are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is

slowing down.

- When a car goes around a circular curve on a horizontal road at constant speed, what force causes it to follow the circular path?

the friction force from the road

- An object weighs 30 N on Earth. A second object weighs 30 N on the moon. Which has a greater mass?

the one on the moon

- The number 0.003010 has

4 significant figures.

-A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bearʹs average speed?

4.0 km/h (v= x/t)

- An airplane increases its speed at the average rate of 15 m/s2. How much time does it take to increase its speed from 100 m/s to 160 m/s?

4.0 s

-A net force of 125 N is applied to a certain object. As a result, the object accelerates with an acceleration of 24.0 m/s2. The mass of the object is

5.21 kg. (f=ma)

- A truck is using a hook to tow a car whose mass is one quarter that of the truck. If the force exerted by the truck on the car is 6000 N, then the force exerted by the car on the truck is

6000 N.

-Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point?

exactly g

- A block of mass m sits at rest on a rough inclined ramp that makes an angle θ with the horizontal. What must be true about force of static friction f on the block?

f = mg sin θ

- A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bearʹs average velocity?

0.00 km/h (v= x/t)

- Write out the number 6.32 × 10-5 in full with a decimal point and correct number of zeros.

0.0000632

- Convert 1.2 × 10-3 to decimal notation.

0.0012

- A cat leaps to try to catch a bird. If the catʹs jump was at 60 ° off the ground and its initial velocity was 2.74 m/s, what is the highest point of its trajectory, neglecting air resistance?

0.29 m (vy2=voy2+2ax)

- A 250-kg motorcycle goes around an unbanked turn of radius 13.7 m at a steady 96.5 km/h. What is the magnitude of the net force on the motorcycle?

1.31 × 104 N (F=mv2/ r)

- 0.0001895 can also be expressed as

1.895 × 10-4.

-If a net force accelerates a 4.5-kg tool at 40 m/s2, what acceleration would that same net force give to an 18-kg tool?

10 m/s2 (f=ma)

- A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a horizontal circle whose diameter is 1.0 m. What is the magnitude of the net force on the ball?

100 N

- A 200-N sled of slides down a frictionless hillside that rises at 37° above the horizontal. What is the magnitude of the force that the surface of the hill exerts on the sled?

160 N

-You are driving home on a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school?

190 mi (v= x/t)

- An object that weighs 75 N is pulled on a horizontal surface by a horizontal pull of 50 N to the right. The friction force on this object is 30 N to the left. What is the acceleration of the object?

2.6 m/s2 (f=ma)

- A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water, assuming negligible air resistance?

20 m (y=Vo T+ 1/2at2)(x=VxT)

- Convert a speed of 4.50 km/h to units of ft/min. (1.00 m = 3.28 ft)

246 ft/min

-A car travels 20 km west and then 20 km south. What is the magnitude of its displacement vector?

28 km

-The graph in the figure shows the position of a particle as it travels along the x-axis. At what value of t is the speed of the particle equal to 0 m/s?

3 s

-When Jeff ran up a hill at 7.0 m/s, the horizontal component of his velocity vector was 6.2 m/s. What was the vertical component of Jeffʹs velocity?

3.2 m/s (pythagorean theorem)

- 0.00325 × 10-8 cm can also be expressed in mm as

3.25 × 10-10 mm.

- A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. What was the average speed of the runner in m/s?

3.95 m/s (v=x / t)

-A karate chop delivers a blow of 3000 N in order to break a board. The force that acts on the hand during this event is actually

3000 N

- An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance away?

30° and 60°

- A 450-kg sports car accelerates from rest to 100 km/h in 4.80 s. What magnitude force does a 68.0 kg passenger experience during the acceleration?

394 N (V=Vo+aT)(f=ma)

- An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is

a horizontal straight line.

- An object is moving with constant non-zero acceleration in the +x direction. The position versus time graph of this object is

a parabolic curve

- An object is moving with constant non-zero acceleration in the +x direction. The velocity versus time graph of this object is

a straight line making an angle with the time axis.

-An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is

a straight line making an angle with the time axis.

- An auto manufacturer advertises that their car can go ʺfrom zero to sixty in eight seconds.ʺ This is a description of what characteristic of the carʹs motion?

average acceleration

which statements about these cars must be true?

both cars have the same acceleration; cars meet at t=10

- The slope of a position versus time graph gives

velocity.

- A hockey puck is set in motion across a frozen pond. If friction from ice and air resistance are neglected, the force required to keep the puck sliding at constant velocity is

zero newtons.