My MX6 was just doing this on the way home. If I stepped on the gas, braked, or turned it would stop. The frequency of the knocking noise would increase with the speed, but seemed louder the slower I was going. The brakes were just done last week. Anyway, in my case the wheel lug nuts were loose, I could just unscrew them by hand! I will be calling the garage tomorrow to let them know.
a dog
First, check the lug nuts. If that's not it, check the wheel bearings.
It's the spirit of the car knocking on the side saying "HELLO??? TAKE ME TO A MECHANIC!"
Bad CV joint, loose rim, Loose caliper
rack and pinion
Front Wheel Drive, could be bad CV Joints, Could be Control arm Bushings...
Check the drive axle for a broken and leaking boot or bad CV joint.
It sounds like you have some steering linkage loose, ie outer tie rod or other front end wheel component that is loose or bad
That sounds like a broken or loose strut assembly.
Check to see if your lug nuts are tight
Many causes and different for front wheel drive and rear wheel drive cars. It's hard to say without more detailed information.
Worn front axle and/or front end component.