Explanation:
For example, when a drum is struck, the flexible skin (sometimes called a membrane) of the drum vibrates. The compression and expansion of the air on either side of the vibrating membrane produces differences in air pressure. The pressure differences generate a sound wave that propagates outward from the drum surface.
Answer:
Period refers to the time for something to happen and is measured in seconds/cycle
Answer:
Torque,
Explanation:
Given that,
The loop is positioned at an angle of 30 degrees.
Current in the loop, I = 0.5 A
The magnitude of the magnetic field is 0.300 T, B = 0.3 T
We need to find the net torque about the vertical axis of the current loop due to the interaction of the current with the magnetic field. We know that the torque is given by :
Let us assume that, 
is the angle between normal and the magnetic field, 
Torque is given by :
So, the net torque about the vertical axis is 
. Hence, this is the required solution.
The answer to this is A. this is because, refraction with a light or sound wave changing its direction involve propagation,(in which propagation is the change in direction of a light or sound wave)
Answer:
D. 24 lb
Explanation:
Tina has been dieting for 13 weeks
First week she lost 3 pounds
Next week she gained 1 pound and did not lose any. This will be subtracted as she has gained a pound
The remaining 11 weeks she lost 2 pounds per week
Weight lost in the 11 weeks = 11×2 =22 pounds
Total weight lost
3-1+22 = 24 lb
Tina has lost 24 pounds in total during the 13 weeks
