1.

An object moving with a constant acceleration of 3 m/s² has a speed of 21 m/s at t=0. What is its speed at t = -5 s ?

a) this is meaningless, there is no such thing as a negative time
b) not enough information is given
c) 0 m/s
d) 3 m/s
*e) 6 m/s

2.

A kangaroo leaps forward, and the horizontal and vertical components of his initial velocity are respectively 4 m/s and 2.8 m/s. At what angle did he take off?

a) 15.0⁰
b) 25.5⁰
*c) 35.0⁰
d) 44.0⁰
e) 45.6⁰

3.

A baseball is hit at an angle of 30⁰ above the horizontal, with an initial speed of 30. m/s. How long does it take for it to reach the highest point in its trajectory?

a) 0.5 s
*b) 1.5 s
c) 2.6 s
d) 3.0 s
e) 4.5 s

4.

A 2000 kg rocket, moving at a speed of 20 km/s turns on its engine to get some acceleration. If the engine produces a constant force during 20 seconds, how far will the rocket travel during this time interval?

a) 400 km
b) 200 km
c) 600 km
d) 800 km
*e) not enough information to answer the question

5.

Which of the following conditions is not possible:

a) to have zero velocity and non zero acceleration
b) to have zero acceleration and non-zero velocity
c) to have positive velocity and negative acceleration
d) to have positive acceleration and negative velocity
*e) they are all possible

6.

Two sled-dogs, each one exerting a force of 25 N, are pulling a 250 kg sled. If friction on the sled is negligible, and the dogs pull at an angle of, respectively, + and - 25⁰, with what acceleration is the sled moving?

a) the sled is not moving, there isn't enough force
b) 0.10 m/s²
c) 0.20 m/s²
d) 0.09 m/s²
*e) 0.18 m/s²

7.

At the starter's signal a racehorse starts running with constant acceleration and, after 4 seconds, is moving at 20 m/s. How far has it gone during this time ?

a) 80 m
*b) 40 m
c) 20 m
d) 10 m
e) none of the above

8.

Two sailboats, "Duck Sloop" and "A Good Ketch" are moving at the same speed. The sloop is moving due North, and the ketch due West. As seen from the sloop, in which direction is the ketch moving?

a) West
*b) South West
c) North West
d) South
e) North East

9.

A simple way to test a person's reaction time, is to hold a pencil vertically, while the person to be tested keeps his fingers open next to the pencil's bottom end, and tries to catch it when the pencil is released. A person with very good reflexes can barely catch a 5 cm pencil. What is his reaction time?

a) 1.0 s
b) 0.60 s
c) 0.45 s
d) 0.30 s
*e) 0.10 s

10.

Trying to escape from a hungry coyote, a rabbit dashes for his hole, which is located behind a wall. Moving at constant speed of 10 m/s, he reaches it by first running for 0.3 seconds due North, and then for 0.4 seconds due East. How far was he from the hole originally, if he could have run in a straight line?

a) 3 m
*b) 5 m
c) 7 m
d) 25 m
e) none of the above

11.

When a horse is pulling a cart on a flat road, the following four forces are present

1- the horse pulling the cart
2- the cart pulling the horse
3- the horse pushing the road
4- the road pushing the horse

Which two form an "action-reaction"pair, as described by Newton's third law?

a) 1 and 4
b) 1 and 3
c) 2 and 4
*d) 3 and 4
e) 2 and 3

12.

If the sum of two vectors $\vec{A}$ and $\vec{B}$ gives a vector parallel to the x-axis, we can state that

a) both $\vec{A}$ and $\vec{B}$ must be parallel to the x-axis
b) at least $\vec{A}$ or $\vec{B}$ must be parallel to the x-axis
c) nothing can be said at all about the vectors or their components
*d) the y-components of $\vec{A}$ and $\vec{B}$ must be equal and opposite
e) the x-components of $\vec{A}$ and $\vec{B}$ must be equal and opposite

13.

Two rams are charging against each other. The younger one moves at a speed of 6.0 m/s and the older at 4.0 m/s. If they are 12 m apart when they start charging, how long will it take for them to collide ?

*a) 1.2 s
b) 2 s
c) 3 s
d) 6 s
e) none of the above

14.

When an apple falls to the ground

a) both apple and earth feel the same force and move with the same acceleration
b) apple and earth feel a different force and move with different accelerations
c) apple and earth feel a different force but move with the same acceleration
*d) apple and earth feel the same force but move with different accelerations
e) not enough information to decide

15.

If the following graph represents velocity vs. time for a given body, we can state that















a) the body covers equal distances in equal times
*b) the body has constant acceleration
c) the body has constant velocity
d) at t=0 the body has 0 acceleration
e) none of the above statements applies to the given graph

16.

You all know that E=mc², where c is the velocity of light, m is mass and E is energy. Based on this knowledge, and dimensionally speaking, which of the following cannot be equivalent to an energy ?

a) a force times a displacement
b) a mass times an acceleration times a distance
c) a mass times the square of a velocity
*d) a force divided by a time
e) they all are

17.

For a given choice of x,y axes, a vector has a negative x component and a positive y component. What can we say about the angle the vector makes with the x axis ?

a) nothing
b) it is between 0 and -90⁰
c) it is larger than 180⁰
*d) it is between 90⁰ and 180⁰
e) none of the above

18.

A car moving on a flat road at 30 mph drives off the edge of a cliff, and hits the ground below after 4 seconds. If the car had been moving at 60 mph, it would have hit the ground after

a) 1 sec
b) 2 sec
c) 3 sec
*d) 4 sec
e) not enough information

19.

As a mailman riding a bicycle at a constant speed = 18 m/s goes by a dog, the dog starts chasing him, accelerating constantly at a rate of 4 m/s². Will the dog catch the mailman, and, if yes, how long will it take him to do so?

a) no, he will not catch him
b) not enough information
*c) 9 seconds
d) 4.5 seconds
e) none of the above

20.

If the two blocks have the same mass, what must be the smallest possible value of the coefficient of friction for the following configuration to be at rest?












a) $\mu$ = 0
b) $0 < \mu < 1$
*c) $\mu$ = 1
d) $\mu \gt 1$
e) not enough information

21.

A 40 kg block and a 10 kg block,connected by a rope, are pulled on a frictionless surface by a 50 N force.What is the acceleration of the 40 kg block?

a) 0.75 m/s²
*b) 1.0 m/s²
c) 1.5 m/s²
d) 1.75 m/s²
e) 2.0 m/s²

22.

A vector has identical components v_x = v_y with respect to a given choice of x,y axis. If we now choose a different set of axes, rotated with respect to the original one

a) the components will change their values, but will still be equal to each other
b) the components will remain the same, but the magnitude of the vector will change
c) both the components and the magnitude of the vector will change
*d) the components will not be equal to each other any longer
e) nothing can be said, unless the angle of rotation is known

23.

A ball is tossed up in the air, and then it falls back to the ground. Neglecting air resistance, and choosing the positive direction to be pointing up, which graph represents its acceleration ?


















c (the acceleration is constant and negative, the correct plot is a horizontal line below the t axis)

24.

A 1500 kg car is traveling at 24 m/s when the driver sees a deer crossing the road and jams the brakes. If the car comes to a stop in 3 sec, what is the road/tire coefficient of friction ?

a) 0.4
b) 0.6
*c) 0.8
d) 1.25
e) 1.5

25.

An eagle carrying a carcass in its talons finds it to be too heavy and drops it, and then keeps flying with the same velocity. When the carcass hits the ground, the eagle will be (neglect air resistance)

*a) overhead of it
b) ahead of it (the carcass has to go a longer distance, therefore it will fall behind)
c) behind it (the carcass is moving faster since it is accelerating)
d) ahead of it, since the eagle keeps flying with constant velocity
e) the answer depends on the actual velocity and/or height of the eagle