# Relative Velocity 1 Relative Velocity Previously we stated

• Slides: 16

Relative Velocity 1

Relative Velocity Previously we stated that all motion is relative 2

Relative Velocity Previously we stated that all motion is relative This includes velocity 3

Relative Velocity Previously we stated that all motion is relative This includes velocity The velocity of an object is compared to a reference point. 4

Relative Velocity Previously we stated that all motion is relative This includes velocity The velocity of an object is compared to a reference point. Frequently that reference point is the observer. 5

The hobo is moving 1. 2 m/s in the boxcar. (relative to the boxcar) The outside observer see the hobo’s motion as 16. 5 m/s relative to the ground. 6

Is the person in the car standing still? 7

Relative Velocity 8

Relative Velocity • Velocity of the bowling ball is relative to the bowling alley 9

Relative Velocity • Velocity of the bowling ball is relative to the bowling alley • The bowling alley is the frame of reference 10

Relative Velocity • Velocity of the bowling ball is relative to the alley • When moving in a straight line, vector subtraction can be used to find the relative velocity of an object 11

Relative Velocity • B represents the bowling ball 12

Relative Velocity • B represents the bowling ball • A represents the bowling alley 13

Relative Velocity • B represents the bowling ball • A represents the bowling alley • Velocity of the ball is relative to the bowling alley 14

Relative Velocity • B represents the bowling ball v = 3. 0 m/s R • A represents the bowling alley v = 0. 0 m/s • The velocity of B relative to A is written as VBA = VB – VA 3. 0 m/s, R - 0. 0 m/s = 3. 0 m/s, R ball This is from the perspective of the alley 15

Relative Velocity • B represents the bowling ball v = 3. 0 m/s R • A represents the bowling alley v = 0. 0 m/s • The velocity of A relative to B is written as VAB = VA – VB 0. 0 m/s -3. 0 m/s, R = -3. 0 m/s, R ball This is from the perspective of the ball 16