Physics Midterm Review - MC Questions

How do we know when to use kinematics?

when the acceleration is constant

4 differences between mass and weight

1. mass = scalar, weight = vector 2. mass = doesn't change w/ location weight = changes w/ location 3. mass SI unit = kg, weight SI unit = N 4. mass = amount of matter in an object, weight = force due to gravity

Newton's 3 Laws of Motion

1: Law of Inertia 2. Law of Acceleration (sum of forces = m*a) 3. Action-Reaction

A net force F is required to give an object with mass m an acceleration of a. If a net force 6F is applied to an object with mass 2m. what is the acceleration of this object. a. 6a b. 3a c. 4a d. a e. 2a

A

An astronaut is on the moon in a space capsule. The acceleration due to gravity on the moon is 1/6 that of earth's gravitational acceleration. How does the mass of the astronaut in the capsule compare to her mass on the earth a. her mass is = to her mass on earth b. her mass is about 1/3 of her mass on earth c. her mass is about 1/2 of her mass on earth d. her mass is about 1/6 of her mass on earth e. her mass is about 1/4 of her mass on earth

A

Light from the sun reaches Earth in 8.40 min. The speed of light is 3.00x10^8 m/s. How far is Earth from the sun? a. 1.51x10^11 m b. 6.02x10^5 m c. 4.2x10^7 km d. 2.14x10^9 m

A

A baseball is hit upward and travels along a parabolic arc before it strikes the ground. Which of the following is necessarily true? a. the velocity of the ball is a maximum when the ball is at the highest point in the arc. b. the x-component of the velocity of the ball is the same throughout the ball's flight. c. the acceleration of the ball is 0 m/s^2 when the ball is at the highest point in the arc. d. the acceleration of the ball decreases as the ball moves upward. e. the velocity of the ball is 0 m/s when the ball is at the highest point in the arc.

B

A bicyclist is riding at a constant speed along a straight-line path. The rider throws a ball straight up to a height a few meters above her head. Ignoring air resistance, where will the ball land? a. this can't be determined w/o knowing speed of rider and max height of ball b. in the same hand that threw the ball c. in the opposite hand to the one that threw it d. behind the rider e. in front of the rider.

B

A net force of 25N is applied for 5.7s to a 12-kg box initially at rest. What is the speed of the box at the end of the 5.7s interval? a. 7.5 m/s b. 12 m/s c. 30 m/s d. 1.8 m/s e. 3.0 m/s

B

A rock is thrown straight up from the earth's surface. Which of the following concerning the NET FORCE acting on the rock at the top of its path is true? a. the direction of the net force changes from up to down b. the net force is = to the weight of the rock c. the net force > the weight of the rock d. the net force < the weight of the rock, but > 0N e. the net force is instantaneously = to 0N

B

A runaway dog walks 0.64 km due north. He then runs due west to a hot dog stand. If the magnitude of the dog's total displacement vector is 0.91 km, what is the magnitude of the dog's displacement vector in the due west direction? a. 0.41 km b. 0.65 km c. 0.52 km d. 0.27 km e. 0.33 km

B

Which of the following is NOT a vector quantity? a. acceleration b. average speed c. displacement d. average velocity e. instantaneous velocity

B

Which of the following is a vector quantity? a. Temperature b. Displacement c. Volume d. Mass e. Time

B

Which of the following quantities is a vector quantity? a. the age of the Earth b. the earth's pull on your body c. the # of people going to a soccer game d. the temp of an iced coffee e. the mass of a freight train

B

A displacement vector is 23 km in length and directed 65 degrees south of east. What are the components of this vector? a. Eastward Component: 0 km, Southward Component: 23 km b. Eastward Component: 21 km, Southward Component: 9.7km c. Eastward Component: 9.7km, Southward Component: 21 km d. Eastward Component: 23 km, Southward Component: 0 km e. Eastward Component: 23 km, Southward Component: 23 km

C

Consider the following forces: (1) frictional (2) gravitational (3) tension (4) strong nuclear (5) normal (6) electromagnetic Which of the forces listed above are considered fundamental forces? a. 1,3, and 5 b. 1, 2, and 4 c. 2, 4, and 6 d. 2, 3, 4, and 6 e. 1, 2, 3, and 5

C

The tendency of an object to maintain its state of motion is called a. Newton's 2nd Law b. Galileo's Principle c. Inertia d. Action-Reaction

C

Which of the following is the longest length? a. 10^2 cm b. 10^4 mm c. 10^5 micrometers d. 10^7 nanometers e. 10^0 m

C

Ball A is dropped from rest from a window. At the same instant, ball B is thrown downward; and ball C is thrown upward from the same window. WHich statement concerning the balls is NECESSARILY true? a. At some instant after it's thrown, the acceleration of ball C is zero. b. All 3 balls strike the ground at the same time. c. All 3 balls have the same velocity at any instant. d. All 3 balls have the same acceleration at any instant. e. All 3 balls reach the ground with the same velocity.

D

In which of the following situations does the car have a westward acceleration? a. The car travels westward at a constant speed. b. The car travels eastward and speeds up. c. The car travels westward and slows down. d. The car travels eastward and slows down. e. The car starts from rest and moves toward the east.

D

Two vectors A and B are added together to form a vector C. The relationship between the magnitudes of the vectors is given by A^2 + B^2 = C^2. Which one of the following statements concerning these vectors is true? a. A and B could have any orientation relative to each other. b. A and B must be parallel. c. A and B could be antiparallel. d. A and B must be at right angles to each other. e. A and B must have equal lengths.

D

Which of the following pairs of units may NOT be added together, even after the appropriate conversions have been made? a. grams and milligrams b. miles and kilometers c. centimeters and yards d. kilograms and kilometers e. seconds and hours

D

Which of the physical quantities is NOT correctly paired with its SI unit? a. velocity m/s b. length m c. speed m/s d. displacement m/s^2 e. speed x time m

D

what is the weight of a 2.50-kg bag of sand on the surface of the earth? a. 9.80N b. 49.0N c. 2.50N d. 24.5N e. 98.0N

D

A football is kicked at an angle θ with respect to the horizontal. Which of the following statements describes the acceleration of the football during this event if air resistance is neglected? a. a is zero m/s^2 at all times. b. a is positive as the football rises, and is negative as the football falls. c. a starts at -9.8 m/s^2 and drops to some constant lower value as the ball approaches the ground. d. a is zero m/s^2 when the football has reached the highest point in its trajectory. e. a is -9.8 m/s^2 at all times.

E

A horse pulls a cart along a flat road. Consider the following 4 forces that arise in this situation. (1) the force of the horse pulling on the cart (2) the force of the cart pulling on the horse (3) the force of the horse pushing on the road (4) the force of the road pushing on the horse Which 2 forces form an "action-reaction" pair that obeys Newton's 3rd law? A) 2 and 4 B) 1 and 4 C) 1 and 3 D) 2 and 3 E) 3 and 4

E

A rock is thrown vertically upward from the surface of the Earth. The rock rises to some max height and falls back toward the Earth. Which one of the following statements concerning this situation is true? a. As the ball rises, its acceleration vector points up. b. The acceleration of the ball is zero when the ball is at its highest point. c. The speed of the ball is negative while the ball falls back toward Earth. d. The velocity and acceleration of the ball always points in the same direction. e. The amount of time for the ball to rise to its max height is the same amount of time for the travel of the rock from the max height back to the Earth.

E

An escaped convict runs 1.70 km due east of the prison. He then runs due north to a friend's house. If the magnitude of the convict's total displacement vector is 2.50 km, what is the direction of his total displacement vector with respect to due east? a. 56 degrees north of east b. 43 degrees south of east c. 34 degrees south of east d. 34 degrees north of east e. 47 degrees north of east

E

The mass of a raindrop is 4 milligrams. Which one of the following statements indicates the correct mass of the raindrop in grams? a. 4x10^3 grams b. 4x10^-6 grams c. 4x10^6 grams d. 4x10^-1 grams e. 4x10^-3 grams

E

What is the difference between a scalar quantity and a vector quantity? Give an example of each.

Scalar = represented with only a magnitude ex. time Vector = represented with both a magnitude and a direction ex. velocity

a ball thrown in the air will never go as far as physics IDEALLY would predict because of...

air resistance

what are the fundamental forces that govern the universe in order from strongest to weakest?

the strong force, electromagnetism, the weak force, gravity