Answer:
Cork
Explanation:
Cork is a solid, other ones are fluid.
You would use negative energy. You change the balls energy by stopping it and oc course it loses energy becasue it has stoped in your hand.
<span>Density is a value for
mass, such as kg, divided by a value for volume, such as m3. Density is a physical
property of a substance that represents the mass of that substance per unit
volume. To determine the mass, we calculate the volume of the paper and multiply to the density. We do as follows:
Volume = 76 mm x 215.9 mm x 279.4 mm = 4584506.96 mm^3 or 4584.51 cm^3
Mass = 1.20 g/cm^3 ( 4584.51 cm^3 ) = 5501.41 g</span>
Answer:
Explanation:
Given
Wavelength of radiation 
We know Energy of wave with wavelength 
is given by
where h=Planck's constant
c=velocity of light
=wavelength of wave
Hence the energy of the wave with wavelength 784 m is 
Answer:
a) Δφ = 1.51 rad
, b) x = 21.17 m
Explanation:
This is an interference problem, as they indicate that the distance AP is on the x-axis the antennas must be on the y-axis, the phase difference is
Δr /λ = Δfi / 2π
Δfi = Δr /λ 2π
Δr = r₂-r₁
let's look the distances
r₁ = 57.0 m
We use Pythagoras' theorem for the other distance
r₂ = √ (x² + y²)
r₂ = √(57² + 9.3²)
r₂ = 57.75 m
The difference is
Δr = 57.75 - 57.0
Δr = 0.75 m
Let's look for the wavelength
c = λ f
λ = c / f
λ = 3 10⁸ / 96.0 10⁶
λ = 3.12 m
Let's calculate
Δφ = 0.75 / 3.12 2π
Δφ = 1.51 rad
b) for destructive interference the path difference must be λ/2, the equation for destructive interference with φ = π remains
Δr = (2n + 1) λ / 2
For the first interference n = 0
Δr = λ / 2
Δr = r₂ - r₁
We substitute the values
√ (x² + y²) - x = 3.12 / 2
Let's solve for distance x
√ (x² + y²) = 1.56 + x
x² + y² = (1.56 + x)²
x² + y² = 1.56² + 2 1.56 x + x²
y2 = 20.4336 +3.12 x
x = (y² -20.4336) /3.12
x = (9.3² -20.4336) /3.12
x = 21.17 m
This is the distance for the first minimum
