Physics 1 Calculus Based Chapters 2-4 Practice Tests Answers

Which of the following is NOT an example of accelerated motion?

Horizontal component of projectile motion

The magnitude of a vector can never be less than the magnitude of one of its components.

True

The area under a velocity-time graph represents:

displacement

A vector 𝑆⃗ of magnitude 6 and another vector 𝑇⃗⃗ have a resultant of magnitude 12. The vector 𝑇⃗:

must have a magnitude of at least 6 but no more than 18

If |𝐴⃗ + 𝐵⃗⃗| = 𝐴 + 𝐵 and neither 𝐴⃗ nor 𝐵⃗ vanish, then

𝐴⃗ and 𝐵⃗⃗ are parallel and in the same direction

A vector of magnitude 20 is added to a vector of magnitude 25. The magnitude of this sum can be

12

A plane traveling north at 200 m/s turns and then travels south at 200 m/s. The change in its velocity is:

400 m/s south

Sally starts from home, walks 300 m east and then 500 m south, and arrives at her school. How far, in a straight line, is Sally's school from her home?

580 m

As a rocket is accelerating vertically upward at 9.8 m/s2 near the Earth's surface, it releases a projectile. Immediately after release the acceleration of the projectile is:

9.8 m/s2 down

Of the following situations, which one is impossible?

A body having constant velocity and variable acceleration

Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any significant air resistance. Compare the time it takes each of them to reach the lake below

Alice and Tom will reach the surface of the lake at the same time.

Vectors 𝐴⃗ and 𝐵⃗⃗ lie in the xy plane. We can deduce that 𝐴⃗ = 𝐵⃗⃗ if:

Ax = Bx and Ay = By

If the acceleration of an object is negative, the object must be slowing down.

False

Which of the following is NOT true of an object in free fall in the absence of air resistance?

If its initial velocity is zero, its position below its starting point can be calculated knowing only how long ago it began falling

What is the relationship between instantaneous speed and instantaneous velocity?

Instantaneous speed is the magnitude of the instantaneous velocity.

When can you treat a moving object as if it were a point-like particle?

Only if all parts of the object are moving in the same direction and at the same rate.

What is the difference between speed and velocity?

Speed is the magnitude of velocity; velocity is a vector and has both magnitude and direction

A feather, initially at rest, is released in a vacuum 12 m above the surface of the Earth. Which of the following statements is correct?

The acceleration of the feather remains constant during the fall

Which of the following is an accurate statement?

The magnitude of a vector is independent of the coordinate system used.

Which of the following is correct?

The only type of vector multiplication that gives a vector result is the cross product.

If the dot product of two nonzero vectors is zero, the vectors must be perpendicular to each other.

True

If the graph of the position as a function of time for an object is a horizontal line, that object cannot be accelerating.

True

Is it possible for an object to have zero velocity and constant nonzero acceleration?

Yes, but its velocity must only be zero for an instant.

Can an object have positive acceleration and decreasing speed?

Yes, this is possible if the initial velocity is negative.

You leave your house and drive to your friend's house, where you stay a while. Then you come back home. Which of the following must be true of your trip?

Your average velocity was zero.

The velocity of a projectile equals its initial velocity added to

a constantly increasing downward velocity

A stone is tied to a string and whirled at constant speed in a horizontal circle. The speed is then doubled without changing the length of the string. Afterward the magnitude of the acceleration of the stone is:

four times as great

The vector −𝐴⃗ is

in the direction opposite to 𝐴⃗

For general projectile motion, when the projectile is at the highest point of its trajectory

its velocity is perpendicular to the acceleration

An object is shot vertically upward. While it is rising:

its velocity is upward and its acceleration is downward

Throughout a time interval, while the speed of a particle increases as it moves along the x axis, its velocity and acceleration could be

negative and negative, respectively

When can we be certain that the average velocity of an object is always equal to its instantaneous velocity?

only when the velocity is constant

We say that the displacement of a particle is a vector quantity. Our best justification for this assertion is:

operating with displacements according to the rules for manipulating vectors leads to results in agreement with experiments

A stone thrown from the top of a tall building follows a path that is:

parabolic

A particle moves at constant speed in a circular path. The instantaneous velocity and instantaneous acceleration vectors are:

perpendicular to each other

Velocity is defined as:

rate of change of position with time

Acceleration is defined as

rate of change of velocity with time

A bullet shot horizontally from a gun:

strikes the ground at approximately the same time as one dropped vertically from the same point at the same instant

Two bodies are falling with negligible air resistance, side by side, above a horizontal plane. If one of the bodies is given an additional horizontal acceleration during its descent, it:

strikes the plane at the same time as the other body

The average speed of a moving object during a given interval of time is always

the distance covered during the time interval divided by the time interval

The position of an object as a function of time is given in meters by x = (at + bt2)𝑖̂+ (ct)𝑗̂. What is its velocity as a function of time?

v = (a + 2bt)𝑖̂+ (c)𝑗

A particle moves from point x1 to point x2. Its displacement is given by

x2 - x1

A particle moves along the x axis from xi to x f . Of the following values of the initial and final coordinates, which results in the displacement with the largest magnitude?

xi = -4m, x f = 4m