If you haven't done so already, replace your engine mounts. Also, bad axles can cause a vehicle to vibrate, not just unbalanced wheels.
if the vibration is above the range of human hearing which is about 20khz
mainly two types of Vibration measurement: shaft vibration Bearing Vibration
The Earth's lithosphere, which includes the rigid outer layer of the Earth's surface where seismic waves travel through, is located directly above the source of vibration.
it is right above the drain plug onnthe bottom of the tranny
behind the motor.. between the motor and firewall, just above the cv shafts
There is pressure in all water because of the weight of the water above it pressing down
The force exerted by the air on an object is known as air pressure. Air pressure is the result of the weight of air molecules above the object pressing down on it.
Driving at 50mph or above what causes a loud knocking clicking sound during acceleration?
It is probably an out of balance tire, next check wheel bearings.
check the front shocks or struts to see if they are worn out, worn out struts could cause the front tires to hop at higher speed.
check front axle bearings.
The air has the weight of all the air above it pressing down on it. this compresses the air increasing its density. So air at sea level is more dense than air on the top of the mountain, since the air on the mountain top has less air above it pressing down.