Answer:
9.6 km/h
Explanation:
20 minutes=1/3 minute.
The speed of the bicycle: 3.2:1/3=9.6 km/h.
Answer: 9.6 km/h
Since you already gave us the weight of the 2.5-kg box,
we don't even need to know what the distance is, just
as long as it doesn't change.
Look at the formula for the gravitational force:
F = G m₁ m₂ / R² .
If 'G', 'm₁' (mass of the Earth), and 'R' (distance from the Earth's center)
don't change, then the Force is proportional to m₂ ... mass of the box,
and you can write a simple proportion:
(6.1 N) / (2.5 kg) = (F) / (1 kg)
Cross-multiply: (6.1 N) (1 kg) = (F) (2.5 kg)
Divide each side by (2.5 kg): F = (6.1N) x (1 kg) / (2.5 kg) = 2.44 N .
9.8 ms^-2 is acceleration
To solve this problem we will apply the concepts related to the electric field such as the smelting of the Force and the load (In this case the force is equivalent to the weight). Later we will apply the ratio of the total charge as a function of the multiplication of the number of electrons and their individual charge.
![E = \frac{mg}{q}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7Bmg%7D%7Bq%7D)
Here,
m = mass
g = Acceleration due to gravity
Rearranging to find the charge,
![q = \frac{mg}{E}](https://tex.z-dn.net/?f=q%20%3D%20%5Cfrac%7Bmg%7D%7BE%7D)
Replacing,
![q = \frac{(3.37*10^{-9})(9.8)}{11000}](https://tex.z-dn.net/?f=q%20%3D%20%5Cfrac%7B%283.37%2A10%5E%7B-9%7D%29%289.8%29%7D%7B11000%7D)
![q = 3.002*10^{-12}C](https://tex.z-dn.net/?f=q%20%3D%203.002%2A10%5E%7B-12%7DC)
Since the field is acting upwards the charge on the drop should be negative to balance it in air. The equation to find the number of electrons then is
![q = ne](https://tex.z-dn.net/?f=q%20%3D%20ne)
Here,
n = Number of electrons
e = Charge of each electron
![n = \frac{q}{e}](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7Bq%7D%7Be%7D)
Replacing,
![n = \frac{3.002*10^{-12}}{1.6*10^{-19}}](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B3.002%2A10%5E%7B-12%7D%7D%7B1.6%2A10%5E%7B-19%7D%7D)
![n = 2.44*10^7](https://tex.z-dn.net/?f=n%20%3D%202.44%2A10%5E7)
Therefore the number of electrons that reside on the drop is ![2.44*10^7](https://tex.z-dn.net/?f=2.44%2A10%5E7)