(a) 
According to Newton's second law, the force experienced by each balloon is given by:
F = ma
where
m = 0.021 kg is the mass
a = 1.1 m/s^2 is the acceleration
Substituting, we found:

The electrostatic force between the two balloons can be also written as

where
k is the Coulomb's constant
Q is the charge on each balloon
r = 16 m is their separation
Since we know the value of F, we can find Q, the magnitude of the charge on each balloon:

(b)
electrons
The magnitude of the charge of one electron is

While the magnitude of the charge on one balloon is

This charge can be written as

where N is the number of electrons that are responsible for this charge. Solving for N, we find:

Scale: (soft 1-->6 hardest)
<span>1=Talc 2=Gypsum 3=Calcite 4=Fluorite 5=Apatite 6=Orthoclase
</span>Mineral #1 can only scratch two other minerals therefore it must have a hardness level of 2+1=3 which is Calcite. (scratches talc, gypsum)
Mineral #2 can scratch four other minerals therefore it must have a hardness level of 4+1=5 which is Apatite. (scratches all but Apatite, Orthoclase)
Looking through the possible conclusions.. It looks like answer is D.
Answer:
35.28m/s; 63.50m
Explanation:
<u>Given the following data;</u>
Time, t = 3.6 secs
Since it's a free fall, acceleration due to gravity = 9.8m/s²
Initial velocity, u = 0
To find the final velocity, we would use the first equation of motion;
Substituting into the equation, we have;
V = 35.28m/s
Therefore, the final velocity of the penny is 35.28m/s.
To find the height, we would use the second equation of motion;

Substituting the values into the equation;



S = 63.50m
Therefore, the height of the tower is 63.50m.
Answer:
1.95m/s
Explanation:
Please view the attached file for the detailed solution.
The following were the conversion factors used in order to express all quatities in SI units:

The loudness<span> of a sound is linked to the size of the vibration which produces it. A big vibration makes a louder sound. Scientists use the word '</span>amplitude<span>' for the size of waves. For waves on water, it is easy to measure the </span>amplitude<span>.</span>