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3 years ago

18 POINTS!!

Physics

1 answer:

Vitek1552 [10]3 years ago

3 0

Answer:

Objects are not pulled towards you due to friction

Explanation:

For example, if you consider a notebook, there is a friction between the notebook and the surface on which the notebook is placed. This frictional force cannot be overcome by the gravitational force as gravitational forces are extremely weak forces so the notebook stays in place.

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In a compression wave, particles in the medium move

nikdorinn [45]

in the same direction as the wave

Explanation:

In a compression wave, the particles in the medium moves in the same direction as the wave source.

A wave is generally defined as a disturbance that transmits energy.

There are two types of waves based on the direction through which they are propagated.
Transverse waves are directed perpendicularly in the direction of propagation.
Examples are electromagnetic waves.
Longitudinal waves are parallel to their source. Examples are sound waves, p-waves.
They are made up of series of rarefaction and compression.

learn more:

Waves brainly.com/question/3183125

#learnwithBrainly

8 0

3 years ago

How old is donald trumpp------ i NEED answer .

professor190 [17]

Donald trump is 74 years old

7 0

3 years ago

How much of the electromagnetic spectrum is visible to us?

mihalych1998 [28]

we only see wavelengths from 400–700 nanometers.

3 0

3 years ago

Read 2 more answers

The 1.53-kg uniform slender bar rotates freely about a horizontal axis through O. The system is released from rest when it is in

OlgaM077 [116]

Answer:

The spring constant = 104.82 N/m

The angular velocity of the bar when θ = 32° is 1.70 rad/s

Explanation:

From the diagram attached below; we use the conservation of energy to determine the spring constant by using to formula:

$T_1+V_1=T_2+V_2$

$0+0 = \frac{1}{2} k \delta^2 - \frac{mg (a+b) sin \ \theta }{2} \\ \\ k \delta^2 = mg (a+b) sin \ \theta \\ \\ k = \frac{mg(a+b) sin \ \theta }{\delta^2}$

Also;

$\delta = \sqrt{h^2 +a^2 +2ah sin \ \theta} - \sqrt{h^2 +a^2}$

Thus;

$k = \frac{mg(a+b) sin \ \theta }{( \sqrt{h^2 +a^2 +2ah sin \ \theta} - \sqrt{h^2 +a^2})^2}$

where;

$\delta$ = deflection in the spring

k = spring constant

b = remaining length in the rod

m = mass of the slender bar

g = acceleration due to gravity

$k = \frac{(1.53*9.8)(0.6+0.2) sin \ 64 }{( \sqrt{0.6^2 +0.6^2 +2*0.6*0.6 sin \ 64} - \sqrt{0.6^2 +0.6^2})^2}$

$k = 104.82\ \ N/m$

Thus; the spring constant = 104.82 N/m

The angular velocity can be calculated by also using the conservation of energy;

$T_1+V_1 = T_3 +V_3 \\ \\ 0+0 = \frac{1}{2}I_o \omega_3^2+\frac{1}{2}k \delta^2 - \frac{mg(a+b)sin \theta }{2} \\ \\ \frac{1}{2} \frac{m(a+b)^2}{3} \omega_3^2 + \frac{1}{2} k \delta^2 - \frac{mg(a+b)sin \ \theta }{2} =0$

$\frac{m(a+b)^2}{3} \omega_3^2 + k(\sqrt{h^2+a^2+2ah sin \theta } - \sqrt{h^2+a^2})^2 - mg(a+b)sin \theta = 0$

$\frac{1.53(0.6+0.6)^2}{3} \omega_3^2 + 104.82(\sqrt{0.6^2+0.6^2+2(0.6*0.6) sin 32 } - \sqrt{0.6^2+0.6^2})^2 - (1.53*9.81)(0.6+0.2)sin \ 32 = 0$

$0.7344 \omega_3^2 = 2.128$

$\omega _3 = \sqrt{\frac{2.128}{0.7344} }$

$\omega _3 =1.70 \ rad/s$

Thus, the angular velocity of the bar when θ = 32° is 1.70 rad/s

7 0

3 years ago

1. El puente mas largo del mundo es el puente Akashi Kaikyo, en Japón. El puente mide 3910 m de largo y está construido con acer

bearhunter [10]

Answer:

It's 1.0000042 times longer in summer than in winter. It represents a 1.6 centimeters difference between seasons.

Explanation:

The linear coefficient of thermal expansion for steel is about $1.2*10^{-7}\°C^{-1}$ . From the equation of linear thermal expansion, we have:

$L_f=L_0(1+\alpha\Delta T)$

Taking the winter day as the initial, and the summer day as the final, we can take the relationship between them:

$L_{summer}=L_{winter}[1+(1.2*10^{-7}\°C^{-1})(30\°C+5\°C)]\\\\L_{summer}=(1.0000042)L_{winter}$

It means that the bridge is 1.0000042 times longer in summer than in winter. If we multiply it by the length of the bridge, we obtain that the difference is of about 1.6 centimeters between the two seasons.

8 0

4 years ago