Frame of Reference

A place or object used for comparison to determine if another object is in motion is called a

• comparison point
• reference point
• point of view
• motion detector

Relative motion

• the motion of an object in comparison to other objects in a specific frame of reference

• the point of view used to measure the position and movement of objects

• how fast something moves

• the distance

The president’s airplane, Air Force One, flies at 250 m/s to the east (compared to the ground). The president visits the pilots in the cockpit. Then he walks to the back of the plane at 1 m/s. What is his speed relative to the ground?

• 249 m/s

• 251 m/s

• 253 m/s

• 248 m/s

If a car passes you going 90 km/hr north while you are driving 80 km/hr north, how far is the car moving relative to your car

• 170 km/hr N

• 170 km/hr S

• 10 km/hr S

• 10 km/hr N

A passenger at the rear of a train traveling at 15 m/s relative to Earth throws a baseball with a speed of 15 m/s in the direction opposite the motion of the train.

What is the velocity of the baseball relative to Earth as it leaves the thrower’s hand?

• 30 m/s

• 15 m/s

• 0 m/s

• 20 m/s

A spy runs from the front to the back of a ship at a speed of 3.0 m/s. If the ship is moving forward at 18.0 m/s, how fast does the spy appear to

be running when viewed by someone watching from the shore?

• 14.5 km/hr

• 15.0 m/s

• 21.0 m/s

• 63 m/s

Tags

NGSS.MS-PS3-1

The best reference points are stationary (not moving).

• true

• false

A baseball pitcher is warming up as he travels to a game by plane. The plane is flying at 250 m/s North relative to the ground. The pitcher throws the ball at 50 m/s South relative to the airplane. What is the ball’s velocity relative to the ground?

• 200 m/s South

• 200 m/s North

• 250 m/s South

• 250 m/s North

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

A boat is travelling upstream at 5 km/h [N] relative to the shore. If there is a current of 7 km/h [S], what is the boat’s velocity relative to the water?

• 2 km/h N

• 2 km/h S

• 12 km/h N

• 12 km/h S

Tags

NGSS.MS-PS2-2

How fast does the plane appear to be moving to a person riding in the car?

• 520 m/s
• 460 m/s
• 30 m/s
• 490 m/s

Tags

NGSS.MS-PS3-1