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2 years ago

Can a flashlight cause skin cancer

Physics

1 answer:

gizmo_the_mogwai [7]2 years ago

4 0

Answer:

Explanation:

It doesn't use the same UV rays as the sun, but it can still damage other cells.

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5. The net external force on a rock of mass 4.2 kg is 8.0 N forward. Find the acceleration of the rock.

andreev551 [17]

Answer:

1.904

Explanation:

F= ma

8 = 4.2 a

a = 8/4.2

a = 1.904

6 0

1 year ago

Blood in a carotid artery carrying blood to the head is moving at 0.15 m/s when it reaches a section where plaque has narrowed t

sp2606 [1]

Answer:

26.9 Pa

Explanation:

We can answer this question by using the continuity equation, which states that the volume flow rate of a fluid in a pipe must be constant; mathematically:

$A_1 v_1 = A_2 v_2$ (1)

where

$A_1$ is the cross-sectional area of the 1st section of the pipe

$A_2$ is the cross-sectional area of the 2nd section of the pipe

$v_1$ is the velocity of the 1st section of the pipe

$v_2$ is the velocity of the 2nd section of the pipe

In this problem we have:

$v_1=0.15 m/s$ is the velocity of blood in the 1st section

The diameter of the 2nd section is 74% of that of the 1st section, so

$d_2=0.74d_1$

The cross-sectional area is proportional to the square of the diameter, so:

$A_2=(0.74)^2 A_1=0.548 A_1$

And solving eq.(1) for v2, we find the final velocity:

$v_2=\frac{A_1 v_1}{A_2}=\frac{A_1 (0.15)}{0.548 A_1}=0.274 m/s$

Now we can use Bernoulli's equation to find the pressure drop:

$p_1 + \frac{1}{2}\rho v_1^2 = p_2 + \frac{1}{2}\rho v_2^2$

where

$\rho=1025 kg/m^3$ is the blood density

$p_1,p_2$ are the initial and final pressure

So the pressure drop is:

$p_1 - p_2 = \frac{1}{2}\rho (v_2^2-v_1^2)=\frac{1}{2}(1025)(0.274^2-0.15^2)=26.9 Pa$

8 0

2 years ago

Is kinetic energy is always transformed into potential energy.

serious [3.7K]

Potential energy is energy stored in an object due to its position or arrangement. Kinetic energy is energy of an object due to its movement - its motion. All types of energy and be transformed into other types of energy. This is true for potential and Kinetic energy as well.

6 0

2 years ago

Which statement explains why a red rose does not appear to be orange?

navik [9.2K]

Answer:

Explanation:

you see red because it's reflected and other colors are absorbed, light transmitted through something is when it travels through something like glass or a gem

7 0

2 years ago

A curve of radius 166 m is banked at an angle of 11°. An 736-kg car negotiates the curve at 81 km/h without skidding. Neglect th

lianna [129]

Answer:

$F_n = 7509.33\ N$