Explain how the visible light spectrum is a spectrum within a spectrum.

19. Find the recoil velocity of a 65 kg ice hockey goalie who

Alexxx [7]

Answer:

c. 0.12 m/s

Explanation:

by using momentum formula $v_2=\frac{m_1\times v_1}{m_1+m_2}$

we get

$v_2=\frac{0.15\times 50}{0.15+65}=0.12$

4 0

3 years ago

Explain how the visible light spectrum is a spectrum within a spectrum.

Dahasolnce [82]

Answer:

In the visible spectrum of light, the color of the light depends on the frequency. The visible spectrum is always the same for a rainbow or the separated light from a prism. The order of colors is red, orange, yellow, green, blue, indigo, and violet.

Explanation:

7 0

3 years ago

A wire of resistivity ρ must be replaced in a circuit by a wire of the same material but four times as long. If, however, the to

Elanso [62]

Answer:

E. two times the original diameter

Explanation:

Resistance of a wire is:

R = ρ L/A

where ρ is the resistivity of the material, L is the length, and A is the cross-sectional area.

For a round wire with diameter d:

R = ρ L / (¼ π d²)

The two wires must have the same resistance, so:

ρ₁ L₁ / (¼ π d₁²) = ρ₂ L₂ / (¼ π d₂²)

The wires are made of the same material, so ρ₁ = ρ₂:

L₁ / (¼ π d₁²) = L₂ / (¼ π d₂²)

The new length is four times the old, so 4 L₁ = L₂:

L₁ / (¼ π d₁²) = 4 L₁ / (¼ π d₂²)

1 / (¼ π d₁²) = 4 / (¼ π d₂²)

Solving:

1 / (d₁²) = 4 / (d₂²)

(d₂²) / (d₁²) = 4

(d₂ / d₁)² = 4

d₂ / d₁ = 2

So the new wire must have a diameter twice as large as the old wire.

3 0

3 years ago

which element are you most likely to find as a free element rather than a compound lead or calcium, explain?

TEA [102]

Pb, if compared to Ca it is less reactive and it is a transition metal, and is highly stable alone.

8 0

3 years ago

E Describe the meaning of a line crossing the x-axis in a<br> velocity-time graph.

gizmo_the_mogwai [7]

Answer:

A line crossing the x-axis in a velocity-time graph means that the moving object has changed its direction.

Explanation:

Velocity-Time graph:

A velocity-time graph is a two dimensional graph with velocity at its y-axis and time at its x-axis. At any point, value of y represents the velocity and value of x represents the time. The slope of the graph gives us the acceleration or deceleration of the moving object.

In a velocity-time graph:

- A straight line represents constant velocity.

- A diagonal line means that the velocity of a body is changing.

*Referring to the figure attached with the answer*

The velocity of the moving object increases at a constant rate for the first 10 minutes. Then the velocity is 60 m/min for the next 5 minutes. After that the velocity is decreasing. Till 30th minute when the velocity is at 0 m/min.

What happens here?

Velocity is a vector quantity. It has some direction. In a velocity-time graph, we are only concerned with two directions of velocity:

- Forward direction

- Backward direction

So, the object stops at 30th minute and starts moving in the reverse direction after that with an increasing velocity. <u>The point where the line cuts the x-axis is basically the point where the object starts moving in the reverse direction.</u>

8 0

3 years ago