Answer:
The gravitational force is 3.509*10^17 times larger than the electrostatic force.
Explanation:
The Newton's law of universal gravitation and Coulombs law are:
Where:
G= 6.674×10^−11 N · (m/kg)2
k = 8.987×10^9 N·m2/C2
We can obtain the ratio of these forces dividing them:
--- (1)
The mass of the moon is 7.347 × 10^22 kilograms
The mass of the earth is 5.972 × 10^24 kg
And q1=q2=Na*e=(6.022*10^23)*(1.6*10^-19)C=9.635*10^4 C
Replacing these values in eq1:
Therefore
This means that the gravitational force is 3.509*10^17 times larger than the electrostatic force, when comparing the earth-moon gravitational field vs 1mol electrons - 1mol protons electrostatic field
Complete Question
An athlete at the gym holds a 3.0 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg. Assume, a bit unrealistically, that the athlete's arm is uniform.
What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? Include the torque due to the steel ball, as well as the torque due to the arm's weight.
Answer:
The torque is 
Explanation:
From the question we are told that
The mass of the steel ball is 
The length of arm is 
The mass of the arm is 
Given that the arm of the athlete is uniform them the distance from the shoulder to the center of gravity of the arm is mathematically represented as
=> 
=> 
Generally the magnitude of torque about the athlete shoulder is mathematically represented as
=> 
=>
Answer:
Velocity of throwing = 34.335 m/s
Explanation:
Time taken by the tennis ball to reach maximum height, t = 0.5 x 7 = 3.5 seconds.
Let the initial velocity be u, we have acceleration due to gravity, a = -9.81 m/s² and final velocity = 0 m/s
Equation of motion result we have v = u + at
Substituting
0 = u - 9.81 x 3.5
u = 34.335 m/s
Velocity of throwing = 34.335 m/s
In order to calculate the angle, we can use the formula below for a constructive interference (the interference is constructive because the fringe is bright):
Where d is the distance between the slits, m is the order of the interference and lambda is the wavelength.
So, using d = 8.25 * 10^-5, m = 2 and lambda = 4.5 * 10^-7, we have:
Therefore the correct option is the second one.
