The mass of the scale pan : 0.11 kg
<h3>Further explanation</h3>
Given
A spiral spring's length = 20 cm
mass 50 g ⇒ the length = 22 cm
mass 70 g ⇒ the length = 22.25 cm
Required
the mass of the scale pan
Solution
Hooke's Law :

The spring constant (k) :

mass of the scale pan=m(for 50 g mass) :

Answer:
–77867 m/s/s.
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 34.5 m/s
Final velocity (v) = –23.9 m/s
Time (t) = 0.00075 s
Acceleration (a) =?
Acceleration is simply defined as the rate of change of velocity with time. Mathematically, it is expressed as:
Acceleration = (final velocity – Initial velocity) /time
a = (v – u) / t
With the above formula, we can obtain acceleration of the ball as follow:
Initial velocity (u) = 34.5 m/s
Final velocity (v) = –23.9 m/s
Time (t) = 0.00075 s
Acceleration (a) =?
a = (v – u) / t
a = (–23.9 – 34.5) / 0.00075
a = –58.4 / 0.00075
a = –77867 m/s/s
Thus, the acceleration of the ball is –77867 m/s/s.
Answer:
The time taken is 6.7 min
Explanation:
Using the linear momentum conservation theorem, we have:

when she was 60.4m from the shuttle, she has zero speed, so the initial velocity is zero.

That is 0.15m/s in the opposite direction of the camera.
the time taken to get to the shuttle is given by:

Answer:
a) There are
electrons in a liter of water.
b) The net charge is -53601707,1 C
Explanation:
a) To find out how many electrons are in a liter of water (equivalent to 1000 grams of water), we have to find out how many molecules of water there are and then multiply it by 10 (e- per molecule).
We can find out how many molecules are by finding the number of moles and then multiplying it by Avogadro's number (number of elements per mol):

b) As all electrons have the same charge, in order to find the net charge of those electrons we have to multiply the charge of a single electron by the number of electrons:

An important clarification is that while the net charge may seem huge, water as a whole is a neutral medium, because there are as many protons as there are electrons, and as they have the same charge, the net charge of water is 0.