Answer:
40m/s
Explanation:
The horizontal component of velocity remains constant because there are no external forces in that direction
By applying motion equations, V= U+ at
where ,
- v - final velocity
- u - initial velocity
- a-acceleration
- t - time
v = u +at
As no force act on the ball ( we neglect air resistance here) no acceleration is seen,
So v = u = 40m/s
85 decibels or higher can cause damage to the human ear.
Decibels is the value of the measurement of sound. Hearing loss can be caused
by noise coming from a loud sound. Noise induced hearing loss maybe permanent
loss or temporary loss. Examples of activities that can give you a noise induced
hearing loss is target shooting, listening to music in your earphones that have
a high volume, and using lawnmowers.
Answer : The final pressure of the system in atm is, 3.64 atm
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

or,

where,
= first pressure = 8.19 atm
= second pressure = 2.65 atm
= first volume = 2.14 L
= second volume = 9.84 L
= final pressure = ?
= final volume = 2.14 L + 9.84 L = 11.98 L
Now put all the given values in the above equation, we get:


Therefore, the final pressure of the system in atm is, 3.64 atm
Currently, many researchers are still working to find them.
Currently , its only theorized and they should be based on the quantum and particle theory
hope this helps
I took this test and the correct answer is c
I hope this helps