B) Light slows down when it passes into a denser medium.
The time taken for the athlete to finish the race is 20 s (Option A)
<h3>What is power? </h3>
Power is simply defined as the rate at which work is done. It can be expressed mathematically as
Power (P) = work (W) / time (t)
But
Work = weight × distance
Therefore,
Power = (weight × distance ) / time
<h3>How to determine the time </h3>
- Mass (m) = 55 Kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Weight = mg = 55 × 9.8 = 539 N
- Power (P) = 5.4 KW = 5.4 × 1000 = 5400 W
- Distance (d) = 200 m
- Time (t) =?
Power = (weight × distance ) / time
5400 = (539 × 200) / t
5400 = 107800 / t
Cross multiply
5400 × t = 107800
Divide both side by 5400
t = 107800 / 5400
t = 20 s
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Answer: it becomes a positive ion
Explanation:
So, when an atom loses 2 electrons there will be no change in the number of neutrons. Therefore, an isotope will not form. Thus, it is concluded that when an atom with no charge loses two electrons, it becomes a positive ion.
Answer:
L = 1.15 m
Explanation:
The diffraction phenomenon is described by the equation
a sin θ = m λ
Where a is the width of the slit, λ the wavelength and m is an integer, the order of diffraction is left.
The diffraction measurements are made on a screen that is far from the slit, and the angles in the experiment are very small, let's use trigonometry
tan θ = y / L
tan θ = sint θ / cos θ≈ sin θ
We substitute in the first equation
a (y / L) = m λ
The first maximum occurs for m = 1
The distance is measured from the center point of maximum, which coincides with the center of the slit, in this case the distance is the total width of the central maximum, so the distance (y) measured from the center is
y = 1.15 / 2 = 0.575 cm
y = 0.575 10⁻² m
Let's clear the distance to the screen (L)
L = a y / λ
Let's calculate
L = 115 10⁻⁶ 0.575 10⁻² / 575 10⁻⁹
L = 1.15 m
Answer:
The magnitude of the torque is 263.5 N.
Explanation:
Given that,
Applied force = 31 N
Distance from the axis = 8.5 m
She applies her force perpendicularly to a line drawn from the axis of rotation
So, The angle is 90°
We need to calculate the torque
Using formula of torque
Where, F = force
d = distance
Put the value into the formula
Hence, The magnitude of the torque is 263.5 N.
