Answer:
19.3 m/s
Explanation:
Considering that no initial velocity was imparted to the hamburger, then we can use the distance covered formula for motion under constant acceleration (that of gravity) and solve for the time it took to reach the ground.
D = vi * t + (1/2) a * t^2
in our case
19 = 0 + 4.9 t^2
t^2 = 19/4.9
then t is approximately 1.97 seconds
We now use this time information in the equation for velocity under accelerated motion (due to gravity)
Vf = Vi + g * t
For our case:
Vf = 0 + 9.8 * 1.97 = 19.3 m/s
<u>A heavy object falls with the acceleration as a light object during free fall because:</u>
Heavy things have a large gravitational force and also have less acceleration. So both the effects exactly cancel and make the falling objects to have the same acceleration irrespective of mass.
Free fall is a unique motion which has only gravitational force that acts on an object. Objects that undergo free fall experience only have the influence of gravity and not any other force.
So when we apply newton's second law of gravity which is:

where,
F is the force
m is the mass
a is the acceleration
For example: When a 1000 kg elephant and a 1 kg rat fall from the same height,
The acceleration can be calculated as follows:
For elephant: F = 10000 N and m = 1000 kg. So,

For rat : F = 10 N and m = 1 kg
Thus, 
Hence, it shows that both the animals have the same acceleration irrespective of their mass.
c. Sodium and potassium
<h3>What is called perspiration?</h3>
Perspiration, water given off by the intact skin, either as vapor by simple evaporation from the epidermis or as sweat, a form of cooling in which liquid actively secreted from sweat glands evaporates from the body surface.
When our body is sweating sodium and potassium is lost from the body along with water.
In order to maintain the integrity of the cells in the body ,Sodium and potassium are very important.
Sweat is also known as perspiration.
So,
By maintaining the proper cell functioning and cell vitality optimum level of sodium and potassium should be maintained in the body.
Learn more perspiration about here:brainly.com/question/1237116
#SPJ1
To solve this question we will use ideal gas equation:

Where:
p = pressure
V = volume
n = number of moles
R = gas constant
T = temperature
We can rearrange formula to get:

We are working woth same gas so we can write following formula. Index 1 stands for conditions before change and index 2 stands for conditions after change.

We are given:
p1=92.1kPa = 92100Pa
V1=200mL = 0.2L
T1=275K
p2= 101325Pa
T2=273K
V2=?
We start by rearranging formula for V2. After that we can insert numbers: