This is 2 hertz. You can mark out 2 full wavelengths in the second of time.
Answer:
D
Explanation:
From the information given:
The angular speed for the block 
Disk radius (r) = 0.2 m
The block Initial velocity is:

Change in the block's angular speed is:

However, on the disk, moment of inertIa is:

The time t = 10s
∴
Frictional torques by the wall on the disk is:

Finally, the frictional force is calculated as:


Answer:
Sundial is an instrument showing the time by the shadow of a pointer cast by the sun on to a plate marked with the hours of the day.
On a Fahrenheit thermometer, the gas becomes 18 degrees warmer.
B) droops.
Why?
To maintain balance, you do not need something short so you're balanced well... You need something long and droopy to maintain balance. The pole should be held by your waist and it should be light.
Hope this helps!~