engineering quiz on motion

Which of the following is a physical quantity that has a magnitude (number and unit) but no direction?

• vector

• scalar

• resultant

• frame of reference

For the winter, a duck flies 10.0 m/s due south against a gust of wind with a speed of 2.5 m/s. What is the resultant velocity of the duck?

• 12.5 m/s south

• –12.5 m/s south

• 7.5 m/s south

• –7.5 m/s south

A student walks from the door of the house to the end of the driveway and realizes that he missed the bus. The student runs back to the house, traveling three times as fast. Which of the following is the correct expression for the return velocity if the initial velocity is v_student?

• 3v_student

• (1/3)v_student

• (1/3)v_student

• –3v_student

Which of the following is the best coordinate system to analyze a painter climbing a ladder at an angle of 60° to the ground?

• x-axis: horizontal along the ground; y-axis: along the ladder

• x-axis: along the ladder; y-axis: horizontal along the ground

• x-axis: horizontal along the ground; y-axis: up and down

• x-axis: along the ladder; y-axis: up and down

In a coordinate system, a vector is oriented at angle θ with respect to the x-axis. The x component of the vector equals the vector’s magnitude multiplied by which trigonometric function?

• cos θ

• cot θ

• sin θ

• tan θ

In a coordinate system, a vector is oriented at angle θ with respect to the x-axis. The y component of the vector equals the vector’s magnitude multiplied by which trigonometric function?

• cos θ

• cot θ

• sin θ

• tan θ

How many displacement vectors shown in the figure above have components that lie along the y-axis and are pointed in the –y direction?

• 0

• 2

• 3

• 5

In a coordinate system, the magnitude of the x component of a vector and θ, the angle between the vector and x-axis, are known. The magnitude of the vector equals the x component

• divided by the cosine of θ.

• divided by the sine of θ.

• multiplied by the cosine of θ.

• multiplied by the sine of θ.

Which of the following is the motion of objects moving in two dimensions under the influence of gravity?

• horizontal velocity

• directrix

• vertical velocity

• projectile motion

Which of the following is an example of projectile motion?

• a jet lifting off a runway

• a thrown baseball

• an aluminum can dropped straight down into the recycling bin

• a space shuttle being launched