Relative Velocity

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

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A hiker walks 5 kilometers due north and then 7 kilometers due east. What is the hiker's resultant displacement?

• 2 km
• 8.6 km
• 12 km
• 12.6 km

Observers using different ___________________ may measure different velocities for an object in motion

• frame of reference

• relatives of motion

• projectile motions

• constant velocity

What is the train's speed with respect to the stationary observer?

• 40 mph

• 50 mph

• 10 mph

• 30 mph

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-1

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

• 10 mph

• 40 mph

• 50 mph

• 30 mph

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

• 30 mph

• 10 mph

• 40 mph

• 50 mph

Tags

NGSS.MS-PS2-1

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