Question

urse ent 38228287 Answer in units of s. 020 (part 1 of 2) 10.0 points A car travels due east with a speed of 54.2 km/h. Rain is falling vertically with respect to Earth. The traces of the rain on the side windows of the car make an angle of 66.5° with the vertical. a) Find the magnitude of the velocity of the rain with respect to the car. Answer in units of km/h. 021 (part 2 of 2) 10.0 points b) Find the magnitude of the rain's velocity with respect to Earth. Answer in units of km/h

Answer 1

A.)

Let the velocity of the car relative to the earth be V(ce), the velocity of the rain relative to earth be V(re), and the velocity of the rain relative to the car be V(rc), then:

V(re) = V(ce) - V(rc)

Horizontally, the rain has zero velocity relative to earth (it falls straight down), so the equation becomes:

0 = 54.3kmh - V(rc)sin66.65°
V(rc) = 54.2km/h / sin66.5°
= 59.101 km/h

B)

The velocity of the rain relative to the earth (vertical components this time) is:

V(re) = 0 - 59.101km/h*(cos66.5° )
= -23.567kmh (minus as the rain is falling downward)

Hope this helps.