Answer:
Explanation:
The problem is related to rotational motion . So we shall find out rotational kinetic energy .
K E = 1/2 x I ω²
ω is the final angular velocity
Moment of inertial of the disk
I ₁ = 1/2 m r²
= .5 x 165 x 2.93²
= 708.25 kgm²
Moment of inertial of the person
I₂ = mr²
= 62.5 x 2.93²
= 536.55 kgm²
ω₂ = v / R
= 3.11 / 2.93 rad /s
At the time of jumping , law of conservation of angular momentum will apply
I₁ ω₁ + I₂ω₂ = (I₁ + I₂)ω
708.25 x0.691 + 536.55 x ( 3.11 / 2.93 ) = ( 708.25 + 536.55 ) ω
ω = 0 .85 rad/ s
K E = 1/2 x I ω²
= .5 x ( 708.25 + 536.55 ) ( .85 )²
449.68 J
<h2>Potential energy lost by 10 N rock will be greater</h2>
Explanation:
Two rocks of 5N and 10N falls from the same height . Thus they will loose the potential energy.
The potential energy lost = mass x acceleration due to gravity x height
The potential energy lost by first 5 N rock = 5 h
Because weight of rock m g = 5 N
Similarly , the potential energy lost by 10 N Rock = 10 h
here weight of rock m g = 10 N
Thus comparing these two , the potential energy lost by 10 N rock is greater than that of 5 N rock .
Answer:
B) 2.7 g of aluminium has a volume of 1 cm^3
Explanation:
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;
If the density of aluminum is 2.7 g/cm³, it simply means that 2.7 g of aluminium has a volume of 1 cm³
Check:
Given the following data;
Mass = 2.7 grams
Volume = 1 cm³
Substituting into the formula, we have;
Density = 2.7 g/cm³
Answer:
The correct answer is B. Statements (i) and (ii) are true.
Explanation:
<u>Fisrt statement:</u>
Electromagnetic radiation such as wave, wavelength λ and oscillation frequency ν are related by a constant, the speed of light. The equation is given by:
So the first statement is true.
<u>Second statement:</u>
The value of c in the vacuum is 3×10⁸ m/s. Hence, the second statement is true.
<u>Third statement:</u>
The speed of any electromagnetic radiation is constant regardless the type of radiation.
Hence, the third statement is false.
Answer:
It looks yellow because that is the only (major) color reflected.
Visible spectra is from about 4000-7000 Angstroms (10^-10 m).
Red are longer wavelengths and blue are the shorter wavelengths.
The Sodium doublet (yellow) occurs around 5900 Angstroms.
