Can someone check if i'm doing this right?

[leehom]

Dubbie is moving directly along a normal line toward a plain mirror at a speed of 3.5 m/s, what is the speed of the image relative to Dubbie?

v Dubbie + v mirror = v image
3.5 m/s + 3.5 m/s = 7.0 m/s


What is the speed of the image, relative to Dubbie, if Dubbie walk away from the mirror surface at 3.5 m/s at an angle of 300 to the mirror surface?

Given:
θ = 300
v= 3.5 m/s

x/v= sinθ
x/(3.5 m/s) = sin300
x = [(3.5 m/s) sin300]
x = 1.75 m/s

 

[leehom]

Sorry.. should be sin 30 deg

 

[Kurdt]

I'm not sure what you're doing for part 2. Have you drawn a diagram of what is happening and what you need to find out? Basically you want to find the velocity normal to the surface of the mirror and double that.