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3 years ago

Exposure to the Sun's harmful infrared radiation should be kept to a minimum.

1 answer:

7 0

Of course! If it's harmful, then your exposure to it should be kept
to a minimum. That's a no-brainer. But the sun's infrared radiation
is generally less harmful than its ultraviolet radiation is.

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A person wants to make a metronome for music practice. He uses a 35-g object attached to a spring to serve as the time standard.

alukav5142 [94]

To develop this problem it will be necessary to apply the concepts related to the frequency of a spring mass system, for which it is necessary that its mathematical function is described as

$f = \frac{1}{2\pi} \sqrt{\frac{k}{m}}$

Here,

k = Spring constant

m = Mass

Our values are given as,

$m = 35g = 35*10^{-3}kg$

$f = 1 Hz$

Rearranging to find the spring constant we have that,

$k = (2\pi f \sqrt{m})^2$

$k = 4\pi^2 f^2 m$

$k = (4) (\pi)^2 (1) (35*10^{-3})$

$k = 1.38N/m$

Therefore the spring constant is 1.38N/m

7 0

4 years ago

Calcular la resistencia de una varilla de grafito de 170 cm de longitud y 60 mm2. Resistividad grafito 3,5 10-5 Ωm

ozzi

Answer:

R = 0.992 Ω

Explanation:

En esta pregunta, dada la información que contiene, debemos calcular la resistencia de la varilla de grafito.

Matemáticamente,

Resistencia = (resistividad * longitud) / Área De la pregunta;

Resistividad = 3,5 * 10 ^ -5 Ωm

longitud = 170 cm = 1,7 m

Área = 60 mm ^ 2 = 60/1000000 = 6 * 10 ^ -5 m ^ 2

Conectando estos valores a la ecuación anterior, tenemos;

Resistencia = (3.5 * 10 ^ -5 * 1.7) / (6 * 10 ^ -5) =

(3.5 * 1.7) / 6 = 0.992 Ω

3 0

3 years ago

Which of the following is a vector quantity?

gizmo_the_mogwai [7]

Answer:

B. 30 m down

Explanation:

In physics we have two types of quantities:

- Scalar quantity: it is a quantity which only has a magnitude (e.g: mass and time are scalar quantities, since they only have a magnitude)

- Vector quantity: it is a quantity which has both a magnitude and a direction (e.g: velocity is a vector quantity, since it has a magnitude (the speed) and a direction)

In this problem, we have:

A. 100 ounces of water --> scalar (this is a volume, which has only a magnitude)

B. 30 m down --> vector (this is a displacement, which has both a magnitude (30 m) and a direction (down)

C. 88 mi/s --> scalar (this is a speed, which has only a magnitude)

D. 45 gallons in a bucket --> scalar (this is a volume, which has only a magnitude)

So, the correct option is B.

4 0

3 years ago

If a skydiver weighs 800 N, what would air resistance be when he is at terminal velocity?

serg [7]

We call "terminal velocity" the constant speed of a falling body
when it is no longer accelerating.

We know that if a body is not accelerating, then the net force
on it is zero.

From the question, we know that the downward force of gravity
on the skydiver is 800 N.

If the 800 N downward plus the air resistance upward add up
to zero, then the air resistance upward must also be 800 N.

5 0

4 years ago

Read 2 more answers

A 1.89 kg object on a frictionless horizontal track is attached to the end of a horizontal spring whose force constant is 4.77 N

Maksim231197 [3]

Answer:

Magnitude F(t)=26.6 N

Direction: -x

Explanation:

Given data

Spring constant K=4.77 N/m

Mass m=1.89 kg

Displace A=5.56m

Time t=3.96s

To find

Magnitude of force F

Solution

The angular frequency is given as

$w=\sqrt{\frac{K}{m} } \\w=\sqrt{\frac{4.77N/m}{1.89kg} }\\w=1.59rad/s$

Force on object is

$F(t)=-mAw^{2}Cos(wt)$

Substitute given values

$F(t)=-(1.89kg)(5.56m)(1.59rad/s)^{2}Cos(1.59*3.96)\\F(t)=-26.6N$

Magnitude F(t)=26.6 N

Direction: -x

4 0

3 years ago