Motion PS

A man jogs at a velocity of 2.5 m/s west for 1,200 s. He then walks at a velocity of 1.0 m/s east for 500 s and then stops to rest. What is the displacement of the man when he stops to rest?

• 3,500 m west

• 2,500 m west

• 3,000 m west

• 700 m west

Point Y lies 0.6 m north and 0.8 m east of Point X. What is the displacement from X to Y?

• 1.0 m, 76° NE

• 1.4 m, 53° NE

• 1.0 m, 53° NE

• 1.4 m, 76° NE

A boat was traveling at 15 mph when a passenger threw an object at 10 mph in the same direction the boat was moving. A friend, standing on the shore, observed the object moving with a speed of 25 mph. The passenger observed the object moving with a speed of 10 mph. Why were the two observations different?

• The current of the river affects the speed of the boat relative to shore.

• The distance between the boat and the shore gave the friend a different viewing angle.

• Objects appear to move more slowly when they move away from the observer.

• The passenger and the friend were watching the object from two different frames of reference.

Andy was driving east with a velocity of 2 meters per second (m/s) relative to the ground. While he was driving, he noticed that he was approaching a road sign.

Which statement correctly describes the motion of the road sign as seen from Andy’s frame of reference?

• The road sign appears to move at a constant 2 m/s to the west.

• The road sign appears to accelerate 2 toward the west.

• The road sign appears to move at a constant 2 m/s to the east.

• The road sign appears to accelerate 2 toward the east.

A skydiver is traveling at a rate of 27 m/s toward the ground. A balloonist is traveling upward at a rate of 2 m/s. The balloonist drops a ball out of the balloon, and after one second, the ball falls at a rate of 10 m/s.

Relative to each other, which objects are moving the fastest?

• the balloonist and the ball

• the skydiver and the balloonist

• the skydiver toward the ground

• the balloonist away from the ground

Marcy is driving on a road parallel to train tracks at a constant velocity. At the same time, a train is accelerating in the opposite direction at a rate of 5 . Marcy hypothesizes that if her car was not moving, the train would appear to accelerate at a slower rate.

Upon which scientific principle has Marcy based her hypothesis?

• Objects in motion have a tendency to maintain their motion.

• For every action, there is an equal and opposite reaction.

• Energy tends to become more disordered with time.

• All motion is relative to a frame of reference.

Two cars drive on the same road. Their speeds in kilometers per hour (km/hr) are identified in the diagram.

What does the driver of Car 1 observe about the changes in the positions of both cars?

• Car 1 is dropping back at a rate of 30 km/hr.

• Car 1 is dropping back at a rate of 65 km/hr.

• Car 2 is pulling away at a rate of 5 km/hr.

• Car 2 is pulling away at a rate of 35 km/hr.

Tags

NGSS.HS-PS2-1

Andrea and Talia are standing still on a moving walkway at the airport. Janette is waiting for them at the end of the walkway.

Which observation is MOST likely made about their relative movement?

• To each other, Andrea and Talia appear to be continually moving.

• To Janette, Andrea and Talia appear to stand still, then move forward.

• To each other, Andrea and Talia appear to be continually moving.

• To Janette, Andrea and Talia appear to be continually moving.

What is the speed of the bus relative to the van?

• 25 mph

• 30 mph

• 55 mph

• 85 mph

The current of a river is flowing south at a speed of 10 kilometers per hour (km/hr). The speedometer on a motorboat moving north indicates the speed of the boat to be 14 km/hr. A person is traveling north on a bicycle along the riverbank.

How fast must the bicycle rider travel so the boat and bicycle appear to be moving at the same speed to an observer on the shore?

• 4 km/hr

• 14 km/hr

• 24 km/hr

• 140 km/hr