Physics Test 2 Study Guide

A dog walks from +4 m to +2 m. What is true about the dog's motion?

Final Displacement is +2m

Rank in decreasing order the distances traveled by objects having the following pairs of average velocity and time of motion. I. Vavg = +2.0 m/s, ∆t =2.0s II. Vavg = +3.0 m/s, ∆t = 2.0s III. Vavg = -3.0 m/s, ∆t = 3.0 s

III, II, I

What is the correct description of any change of position farther to the right of zero?

Positive Displacement

If the average velocity of a duck is zero in a given time interval, what can you say about the displacement of the duck for that interval?

The displacement is zero

If a car is traveling eastward, can its acceleration be westward? Explain your answer, and use an example in your explanation.

Yes. The acceleration could be westward if the car were slowing down.

Velocity can be either positive or negative, depending on the direction of the displacement. The time interval, ∆t, is always positive. Why?

You can't go back in time.

What is the maximum negative displacement a dog could have if it started its motion at +3 m?

-3m (Ask Mrs Hopper)

If the x-component of B equals the magnitude of B, then...?

By equals zero.

A school bus takes 0.530 h to reach the school from your house. If the average velocity of the bus is 19.0 km/h to the east, what is the displacement?

10.07km

Which of the following quantities used to describe motion is an example of a vector quantity? a. distance b. speed c. time d. average velocity

D. average velocity

The Olympic record for the marathon is 2.00 h, 9.00 min, 21.0 s. If the average speed of a runner achieving this record is 5.436 m/s, what is the marathon distance?

42.2km (42188.80m)

What would be the acceleration of a turtle that is moving with a constant velocity of 0.25 m/s to the right?

0, it has constant velocity

A car accelerates from rest at −5.00 m/s². a. What is the velocity at the end of 5.0 s? b. What is the displacement after 5.0 s?

a. -25 m/s b. -62.5 m (Ask Mrs. Hopper)

Sally travels by car from one city to another. She drives for 30.0 min at 60.0 km/h, 10.0 min at 100 km/h, and 45.0 min at 45.0 km/h, and she spends 20.0 min eating lunch and buying gas. a. Determine the average speed for the trip. b. Determine the total distance traveled.

a. 46 km/h (45.95 km/h) b. 80.42 km

The speed of a car will increase if the car's initial velocity is _________ and its acceleration is _________.

initial velocity is positive and its acceleration is positive.

A vector remains unchanged when...?

it is moved parallel to its original direction. (Ask Mrs. Hopper)

In a diagram, the length of a vector arrow represents the...?

magnitude of the vector

The components of a vector are...?

perpendicular

In a diagram, a student draws a vector representing the velocity of a plane traveling at 525 km/h 18.0° east of north as a vector lying along the +x-axis. To represent the velocity of another plane traveling at 478 km/h 75.0° east of north on the diagram, at what orientation with respect to the +x-axis should the student draw this vector?

57° clockwise from the +x-axis

A vector that has components that lie along the -x-axis and the +y-axis is oriented at angle A measured counterclockwise from the +x-axis. Which of the following ranges give the values of angle A? a. 0°<A<90° b. 90° < A < 180° c. 180° < A < 270° d. 270° < A < 360°

B.

Which of the following situations represents a positive displacement of a carton? Assume positive position is measured vertically upward along a y-axis. a. A delivery person waiting for an elevator lowers a carton onto a dolly. b. When the elevator doors open, the delivery person lifts the dolly over the threshold of the elevator. c. The delivery person pushes the dolly to the back of the elevator while pressing a floor button. d. The door closes and the elevator moves from the 10th to the 4th floors.

B.

For a scooter with a negative acceleration, which of the following statements is always true? a. The scooter is losing speed. b. The final velocity of the scooter will be negative. c. The initial velocity of the scooter will be greater than its final velocity. d. The scooter will have a negative displacement.

C. (ask Mrs. Hopper

Rank in decreasing order the displacements of objects having the following pairs of average velocity and time of motion.. I. Vavg = +2.0 m/s, ∆t =2.0s II. Vavg = +3.0 m/s, ∆t = 2.0s III. Vavg = -3.0 m/s, ∆t = 3.0 s

II, I, III