Answer:
Explanation:
Let q be the charges on each spheres , 2d be the distance between them in equilibrium , T be tension in the string and F be the force of repulsion between them
F = k q² /4d²
For equilibrium
T sin15 = F
T cos 15 = mg
tan15 = F / mg
F = mg tan15
k q² /4d² = mg tan15
k q² = 4d² x mg tan15
= 4 x( .7 sin15)² x 3.1 x 10⁻³ x 9.8 x .2679
= 1.068 x 10⁻³
q = .3444 x 10⁻⁶ C
no of electrons
= .3444 x 10⁻⁶ / 1.6 x 10⁻¹⁹
= 215.25 x 10¹⁰
Answer:
Hope this helps! Mark as brainliest if liked thanks!
Explanation:
Your reasoning that the shadow is the shortest at mid-day is spot-on!
The wording of the question is the key to the answer. It says that the measurements were made in Summer. So this means that British Summer Time (BST) is being applied. BST is one hour ahead of Greenwich Mean Time and so what looks like 1pm is really 12 noon.
The safest sort of answer is to say that the shadow is shortest when the sun is at its highest point, and in this particular question that is at 1 pm because it is BST.
Answer:
Efficiency = 10.2 %
Explanation:
Given the following data;
Mass = 70 kg
Height = 50 m
Velocity = 10 m/s
We know that acceleration due to gravity is equal to 9.8 m/s².
To find the efficiency of energy conversion from potential to kinetic;
First of all, we would determine the potential energy;
P.E = mgh
P.E = 70 * 9.8 * 50
P.E = 34300 J
For the kinetic energy;
K.E = ½mv²
K.E = ½ * 70 * 10²
K.E = 35 * 100
K.E = 3500
Therefore, Input energy, I = 34300 J
Output energy, O = 3500 J
Next, we find the efficiency;
Efficiency = O/I * 100
Substituting into the formula, we have;
Efficiency = 3500/34300 * 100
Efficiency = 0.1020 * 100
Efficiency = 10.2 %
Since we have , v=f×lambda (wavelength). Where v equals 350m/s and wavelength equals 3.80. so it will become f = v/lambda=350/3.80=92.1052Hz
Radio waves are used in cell phone wireless communication by this: Radio waves are released from the cell phone and travel to satellites in the stratosphere. After they reach the satellite, they are redirected to the recipient of the call/text.
Hope this helps! Can I have brainliest please?
