Physics Exam Review

The acceleration of an object is______proportional to the net force and______and_______proportional to its mass.

1. directly 2. inversely

Tom the cas is chasing Jerry the mouse on a table. Jerry puts on the brakes and stops, while Tom continues right off the edge of the table at 12.00 m/s. Tom hits the ground 0.80s after leaving the tabletop. 1. Approximately how tall is the table? 2. How far from the base of the table does Tom hit the ground?

1. do= 3.14m or 3.136 2. d= 9.6m

Convert 2000mm into m?

2m

Convert 5,000g into kg?

5kg

Which of the following statements are true of the vertical velocity (Vy) of a projectile? List all that apply.

* the vy value is a constant value of 9.8 m/s * the vy value is changing by 9.8 m/s every second * the vy value is 0 m/s at the peak of a projectile's trajectory.

A rightward-moving car accelerates from 55 m/s to 25 m/s in 4.2 seconds. Determine the magnitude of the average acceleration of the car in m/s^2.

-7.14m/s^2

A teacher does the following: i. walks 2 m, south ii. walks 4 m, east iii. walks 2 m, north iv. walks 4 m, west The overall displacement of the teacher is_____.

0(zero)

A 4-kg object is thrown upwards with an initial velocity of 16 m/s. At the peak of the trajectory, the approximate magnitudes of the net force and acceleration are______N and_______m/s/s.

1. 64 2.-9.8

The diagrams below represent the free-body diagrams for different skydivers at various moments during their fall. What is the acceleration of each skydiver and which Skydiver has reached terminal velocity?

1. Skydiver B 2: A) a=-1.6 B) a=0 C) a=1.26 D) a=.89

A 1.5kg basketball and a 8kg bowling ball are dropped at exactly the same time from exactly the same height. Which object experiences a larger force of gravity? Which ball will hit the ground first?

1. The bowling ball 2. Neither- they hit the ground at the same time.

Use the figure below for question # - # A ball is launched upward with an initial velocity of 15 m/s at an angle of 30° with the horizon. The components of the initial velocity are shown. 1. at which point does the projectile have the largest vertical speed? 2. which position has the largest horizontal speed? 3. what is the vertical velocity of the projectile at point X? 4. what is the vertical velocity of the projectile at point V? 5. what is the horizontal velocity of the projectile at point z? 6. if the projectile is launched from the ground how long is it in the air and how far from where it was launched does it hit the ground?

1. V and X 2. velocity is constant 3. V=0 4. Vy=7.5 m/s 5. Vx= -12.99 m/s 6. 1) t=1.53s 2) R= 19.88m

Late one night, an unfortunate bug collides with the windshield of a fast-moving bus. The force of the bus on the bug is____the force of the bug on the bus; the resulting acceleration of the bug is____the acceleration of the bus.

1. equal 2. more than

A skydiver steps off a plane at an altitude of 10,000 feet. As the skydiver falls, her speed steadily increases. This causes the air resistance force to_____and the acceleration to_____.

1. increase 2. decrease

An object is moving from right to left. The motion is represented by the oil drop diagram at the right. This object has a______velocity and a______acceleration.

1. leftward 2. leftward

Which of the following statements are true of projectile motion? List all that apply.

1.projectiles are objects that experience free fall 2. the acceleration of a projectile is downward 3. if moving fast, projectiles can experience considerable air resistance. 4. gravity is the only force influencing the motion of a projectile

Use the description and figure for question 18 & 19: A football coach starts at the 10-yard line (A) and walks to the 40-yard line (B). He turns around and walks to the 0-yard line (c). He turns around again and walks back to the 50-yard line (D). He turns around once more and walks back to the 25-yard line (E), thus completing his 10 minutes of pacing. 18. The coach's overall displacement is_____. 19. The coach's average velocity is_____.

18. 15 19. 1.5

A 5-ton airplane normally flies at 200 km/hr. If it experiences a 50 km/hr Tailwind (i.e., a wind coming from the tail, forward), then its resultant velocity will be_____km/hr.

250 km/hr

Determine the weight of an 70.0-kg person who is running with a speed of 5.0 m/s.

686N

The net force and the resulting acceleration as experienced by four objects are listed below. Calculate the mass of each object?

A. m=16.8kg b. m=41.6kg c. m=7.25kg d. m=3.83kg

Action and reaction forces always occur in equal and opposite pairs. They do not balance each other because the____.

Action and reaction forces act on different objects.

Different forces are applied to objects of varying mass. The resulting accelerations are shown. Which object experiences the greatest net force?

B

Two projectiles are launched horizontally from the same initial height at different speeds. Projectile A is launched with a speed of 4 m/s and projectile B is launched with a speed of 12 m/s. Which projectile will hit the ground first?

Both at the same time

A vector is a quantity that is fully described by_____.

Both its magnitude and its direction

Aaron Agin is adding vectors for his homework assignment. He adds three vectors and draws the resultant. However, Aaron did not label the resultant. What is the letter of the resultant vector? Use the picture to the right--->

C

Consider the vector below. Draw its x- and y- components.

C

Suppose that an astronaut throws a rock in outer space at a location far from significant influences of gravity and air resistance. One would expect that the rock would____.

Continue in motion with the same speed and direction

A rightward moving object is coasting to a stop along a straight, level surface. The net force acting upon the object Must be_____.

Directed leftward

Which of the following quantities are vectors? Select all that apply.

Displacement, Acceleration, Force

In terms of their definitions, what is essential differences between displacement and distance is that_____.

Distance is a scalar and displacement is a vector.

The acceleration of a projectile is always directed_____.

Downward

A car is moving westward along Lake Avenue and decreasing its speed from 25 mph to 25 mph. The direction of this car's acceleration is_________.

Eastward

A linebacker strikes a fullback with full force in a football game. The reaction force to the force of the linebacker striking the full back is______.

Equal

What net force (in Newton) would cause a 40.0-kg object to experience an acceleration of 3.0 m/s^2?

F=120

A 500-kg upward-moving freight elevator nears its destination and accelerates upward at a rate of 1.8 m/s^2. What is the tension in the cable supporting the elevator?

Ft=5800N

For any given motion, displacement is_____.

How far out of place which the object finishes relative to the starting location.

When all individual forces acting on an object are balanced, it is the natural tendency of an object to_______.

Keep its velocity constant (either at zero or nonzero value) or maintain its state of motion.

A scalar is a quantity that is fully described by_____.

Magnitude alone

The amount of matter or "stuff" in an object is referred to as the_____of the object.

Mass

If an object has an acceleration then it MUST be_____.

Moving

Does the horizontal velocity of a projectile change?

No, its constant.

Force diagrams despicting the magnitude and directions of the forces acting upon four objects are shown below. Each object has the same mass - approximately 5 kg. Which object will experience an acceleration of 6m/s^2?

Object B

Identify the following quantity as being either a scalar or a vector: 55 mi/hr

Scalar

In terms of their definitions, the essential difference between velocity and speed is that_____.

Speed is a scalar and velocity is a vector.

When does a projectile have the greatest acceleration?

The magnitude of the acceleration of a projectile has two local maxima, one at the beginning when it is launched, and one at the end when it strikes its target.

A skydiver pulls the chord of his parachute. The forces acting upon the skydiver and his parachute are shown in the diagram at the right. From this diagram, one might infer that_____.

The person is slowing down.

A sled slides down a hill, reaches the level surface and eventually comes to a stop. The fact that the sled ultimately stops is best explained by_____.

The pressure of unbalanced force (eg.friction) can cause a moving object to stop.

For any given motion, the velocity is_____.

The rate at which an objects position changes

Acceleration is defined as_____.

The rate at which the velocity changes.

Identify the following quantity as being either a scalar or a vector: 9.8 m/s/s, down

Vector

The force of gravity that acts upon an object is referred to as the_____of the object.

Weight

Vectors A, B, and C are being added using the head-to-tail method in order to determine the resultant. Vector A is added first, then B, then C. If the vectors were added in a different order, would the resultant be the same?

Yes

An object is moving along a level surface with a constant velocity. The net force acting upon the object is______.

Zero

Consider the free body diagram shown at the right. Use the numerical value for the individual forces and the approximate value of g (10m/s/s) to determine the acceleration of the object (in units of m/s^2). Assign a negative number to the acceleration if it is leftward or downward.

a=4

Determine the acceleration (in m/s^2) of a 9.0-kg object that experiences a net force of 54.0 N.

a=6 m/s^2

When an object reached terminal velocity, it has stopped____. List all that apply.

accelerating, gaining (or losing) speed

Which of the following statements are True? List all that apply. a. the mass and weight of an object are the same thing. b. the mass of an object is the force of gravity acting upon an object. c. The weight of an object is its mass multiplied by the force of gravity. d. the mass of an object on the moon will be the same as its mass on Earth. f. the weight of an object is the force of gravity acting on it.

c,d,f

The value of g is 9.8 m/s^2 'g' stands for___.

gravity