63 hertz.
This is because a hertz is how often a sound wave repeats.
Answer:
W = 289.70 kg
Explanation:
Given data:
Pressure in tank = 23 atm
Altitude 1000 ft
Air temperature in tank T = 700 F
Volume of tank = 800 ft^3 = 22.654 m^3
from ideal gas equation we have
PV =n RT
Therefore number of mole inside the tank is




we know that 1 mole of air weight is 28.97 g
therefore, tank air weight is 
W = 289.70 kg
Hi there!
Initially, we have gravitational potential energy and kinetic energy. If we set the zero-line at H2 (12.0m), then the ball at the second building only has kinetic energy.
We also know there was work done on the ball by air resistance that decreased the ball's total energy.
Let's do a summation using the equations:

Our initial energy consists of both kinetic and potential energy (relative to the final height of the ball)

Our final energy, since we set the zero-line to be at H2, is just kinetic energy.

And:

The work done by air resistance is equal to the difference between the initial energy and the final energy of the soccer ball.
Therefore:

Solving for the work done by air resistance:


Answer:
Continuing to play if you have an injury can make that injury worse. A small stress fracture that might have healed quickly can grow into a more serious, more painful fracture that will take longer to heal. Returning to play too soon after a concussion increases your risk of serious brain injury.
Explanation: Trust me it right bro
The electrostatic force between two charges q1 and q2 is given by

where

is the Coulomb's constant and r is the distance between the two charges.
If we use F=19.2 N and q1=q2=-3.0 C, we can find the value of r, the distance between the two charges by re-arranging the previous formula: