Relative Motion (2)

What is the walker's speed from the observer's perspective?

• 10 mph

• 40 mph

• 50 mph

• 30 mph

Tags

NGSS.MS-PS3-1

A passenger at the rear of a train traveling at 15 m/s relative to the ground 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 the ground as it leaves the thrower’s hand? In other words: how fast does a person on the ground see the ball move?

• 30 m/s

• 15 m/s

• 0 m/s

• 20 m/s

What is the walker's speed with respect to the train?

• 30 mph

• 10 mph

• 40 mph

• 50 mph

A train is traveling 50 m/s north on a track. A passenger on the train walks to the bathroom 1 m/s to the north. What is the speed of the passenger relative to the train?

• 1 m/s

• 51 m/s

• 49 m/s

• 50 m/s

A dog and a cat are at a stand-off, running towards each other, both at 12 m/s. What is the magnitude of velocity of the cat relative to the dog?

• 12 m/s

• 24 m/s

• 0 m/s

• 6 m/s

A motorboat, which has a speed of 5 m/s in still water, is crossing a river (from west to east) The river's current is flowing south at 3.3 m/s. What is the magnitude of the boat’s resultant velocity with respect to the starting point?

• 3.3 m/s

• 5.0 m/s

• 6.0 m/s

• 8.3 m/s

The president’s airplane, Air Force One, flies at 250 m/s to the east with respect to the air. The air is moving at 35 m/s to the north with respect to the ground. Find the velocity of Air Force One with respect to the ground.

• 252 m/s
• 222 m/s
• 435 m/s
• 125 m/s

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A boat heading north crosses a wide river with a velocity of 10.00 km/h relative to the water. The river has a uniform velocity of 5.00 km/h due east. Determine the boat’s speed with respect to an observer on shore.

• 11.18 km/hr

• 15 km/hr

• 5 km/hr

• 30 km/hr

For us humans, what is our basic reference frame?

• Earth

• The Sun

• The Universe

• The Milky Way Galaxy

When you're in a car, what is your frame of reference?

• the car

• the road

• the Earth

• there is none