Answer:
Explanation:
It is given that,
Mass of the grindstone, m = 3 kg
Radius of the grindstone, r = 8 cm = 0.08 m
Initial speed of the grindstone, 
Finally it shuts off, 
Time taken, t = 10 s
Let 
is the angular acceleration of the grindstone. Using the formula of rotational kinematics as :
Let 
is the number of revolutions of the grindstone after the power is shut off. Now using the third equation of rotational kinematics as :
or
So, the number of revolutions of the grindstone after the power is shut off is 50.
Answer:
I'd go for 'Marie drives a car'
Explanation:
Static electricity will possible form in all the scenarios, but is more likely to form when you're driving a car. This is due to the friction between the body of the car and the particles in the air around the body of the car. This is why chains are sometimes attached to fuel tankers when transporting them. The chain is made to touch the ground so that any charge built up can be safely conducted to the earth, reducing the chances of a fire outbreak due to charges igniting the fuel.
The receiver of a signal must understand the code or language being used to avoid confusion and losses.
<h3>What is a Signal?</h3>
This is usually in the form of a sound or body movement and is involved in conveying messages to people.
The receiver must understand the code or language in order to prevent confusion or loss of lives and properties.
Read more about Signal here brainly.com/question/15304191
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Answer:
a) 0.167 μC/m^2
b) 1.887 * 10^4 V/m
Explanation:
Hello!
First let's find the surface charge density:
a)
Since thesatellite is metallic, the accumalted charge will be uniformly distribuited on its surface. Therefore the charge density σ will be:
σ = Q/A
Where A is the area of the satellite, which is:
A=4πr^2 = πd^2 = π(1.9m)^2
Therefore:
σ = (1.9)/(π (1.9)^2) μC/m^2 = 0.167 μC/m^2
Now let's calculate the electric field
b)
Just outside the surface of the satellite the elctric field will be:
E = σ/ε0
Where ε0=8.85×10^−12 C/Vm
Therefore:
E = (0.167*10^-6 C/m^2) / (8.85*10^-12 C/Vm) = 0.01887 *10^6 V/m
E = 1.887 * 10^4 V/m
The Energy is Kinetic Energy.
Kinetic Energy = 1/2*mv², Where m is mass in kg, v is velocity in m/s
Energy is 33750 Juoles, v = 30m/s
1/2*mv² = E
1/2*m*30² = 33750
m = (2*33750) / (30²) Using a calculator
m = 75 kg
Mass of object is 75 kg.
