Physics Ch. 3

A skier slides onto a horizontal patch of slushy snow at velocity Vskier, and slows to a constant speed without changing direction. Which of the following expressions could be the skiers resulting velocity?

+1/4 Vskier

A car traveling at the legal speed limit has velocity +Vcar with respect to the road. You are in another car traveling in the opposite direction at the legal speed limit with respect to the road. As the first car approaches you, what is its velocity relative to you?

+2Vcar

The velocity of a passenger relative to a boat is -Vpb. The velocity of the boat relative to the river is moving on +Vbr. The velocity of the river to the shore is +Vrs. What is the velocity of the passenger relative to the shore?

-Vpb+Vbr+Vrs

In a diagram, a student draws a vector representing the velocity of a plane traveling at 525 km/h 18 degrees east of north as a vector lying along the +x-axis. To represent the velocity of another plane traveling 478 km/hr 75 degrees east of north on the diagram, at what orientation with respect to the x-axis should the student draw this vector?

57 degrees 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.

90< A <180

Which of the following may be classified by projectile motion?

All of the above

If the x component of B equals the magnitude of B, then

By equals zero

The projection of a vector along the axes of a coordinate system is called

a component of the vector

Which of the following quantities used to describe motion is an example of a vector quantity?

average velocity

Which of the following is a frame of reference from measuring motion?

coordinate system

If vectors move according to the rules of triangle method of vector addition, then the resultant vector is drawn

from the tail of the first vector to the tip of the last vector

For an object to be a projectile, it must be in free fall and its initial velocity must

have a horizontal component

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

magnitude of the vector

In a circus parade, a clown standing on a raised float moving at a constant forward speed drops a fake dumbbell. A child in the bleachers on the sidewalk observes the dumbbell. Who would observe the dumbbell falling backwards?

neither the clown nor the child

A vector remains unchanged

only if it is moved parallel to is original direction

In the absence of air resistance, the path of a projectile is a

parabola

The components of a vector are

perpendicular

In a circus parade, a clown standing on a raised float moving at a constant forward speed drops a fake dumbbell. A child in the bleachers on the sidewalk observes the dumbbell. Ignoring air resistance, who would observe the dumbbell falling straight down?

the clown only

A gardener holds the nozzle of a hose constant at a small angle above the horizontal and observes the path of the stream of water coming from the nozzle. If the pressure of the water is increased so that the water leaves the nozzle at a great speed

the height and width of the water's path will increase

Assuming no air friction and ay= -g, the horizontal displacement of a projectile depends on the

vertical component and the horizontal component of its initial velocity