Answer:
B
Explanation:
Atomic structure contains electrons, protons and neutrons.
Electron is very light compared to proton and neutrons.
Given that the mass of an electron is
A) equal to the mass of a proton
B) less than the mass of a neutron
C) greater than the mass of a proton
D) equal to the mass of a neutron
The correct answer is B which is less than the mass of the neurons.
<h2>
Answer:</h2>
1000th multiple of the standard reference level for intensities.
<h2>
Explanation:</h2>
The sound intensity level (β), measured in decibels, of a sound with an intensity of I is defined as follows;
β = 10 log (I / I₀) --------------------(i)
Where;
I₀ = reference intensity
Given from the question;
β = sound level = 30dB
Substitute this value into equation (i) as follows;
30 = 10 log (I / I₀)
Divide both sides by 3;
3 = log (I / I₀)
Take antilog of both sides;
10^(3) = (I / I₀)
1000 = I / I₀
Solve for I;
I = 1000I₀
Therefore the intensity of the sound is 1000 times the standard reference level for intensities (I₀)
Acceleration can be defined as the rate of change in the velocity of an object. Option C is correct.
<h3>What is
Acceleration?</h3>
- It is defined as the rate of change in velocity.
- It can also be defined as the rate of change in position in a particular direction.
Where,
- acceleration
- change in velocity
- time
Therefore, acceleration can be defined as the rate of change in the velocity of an object.
Learn more about Velocity:
brainly.com/question/2239252
Answer:
Explanation:
a )
Reaction force of the ground
R = mg
= 160 N
Maximum friction force possible
= μ x R
= μ x 160
= .4 x 160
= 64 N .
b )
160 N will act at middle point . 740N will act at distance of 3 / 5 m from the wall ,
Taking moment about top point of ladder
160 x 1.5 + 740 x 3/5 + f x 4 = 900 x 3
240 + 444 + 4f = 2700
f = 504 N
c )
Let x be the required distance.
Taking moment about top point of ladder
160 x 1.5 + 740 x 3 x / 5 + .4 x 900 x 4 = 900 x 3 ( .4 x 900 is the maximum friction possible )
240 + 444 x + 1440 = 2700
x = 2.3 m
so man can go upto 2.3 at which maximum friction acts .
