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4 years ago

Why is it helpful to study the light that comes off stars?

1 answer:

6 0

It is helpful to study the light that comes off stars because C. The light from a star gives hints of what elements make up a star.

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A hockey puck with a mass of 0.175 kg slides over the ice. The puck initially slides with a speed of 5.25 m/s, but it comes to a

Neko [114]

Answer:

1.70 J

Explanation:

The heat dissipated is the difference in the kinetic energies.

This is given by

$E = \frac{1}{2}mv_f^2 - \frac{1}{2}mv_i^2$

$v_i$ and $v_f$ are the initial and final velocities.

With m = 0.175 kg,

$E = \frac{1}{2}\times0.175(2.85^2 - 5.25^2) = -1.701\text{ J}$

The negative sign appears because energy is lost.

7 0

3 years ago

Magnesium is a shiny, flexible metal that can be burned in the presence of air.

alukav5142 [94]

Answer:

A new substance was formed

Explanation:

According to this question, a shiny and flexible metal called Magnesium (Mg) is burnt in air to produce a white powder that has no shiny or flexible properties, however, has more weight than the magnesium metal itself.

This is possible because a CHEMICAL CHANGE has occured, hence, a new substance has been formed. The formation of a new substance during the burning process (chemical reaction), induced the increase in mass.

8 0

3 years ago

When waves travel through water, why do the moving water particles continue to return to their starting position??

Law Incorporation [45]

Waves transfer energy not matter. so simply put, the water doesn't move. it's just being used as a road that energy uses to get from point a to b. it's easier to think of some thing on the water rather than the water it self. like a cork floating on the surface. when a wave passes through the cork. the cork goes up to the peak of the wave and then down to the trough of the wave and then back at equilibrium. it only moved up and down since it was following the wave pattern. if the waves transfered matter as well as energy then the cork would begin to get pushed by the wave and move towards the direction of travel

4 0

4 years ago

Read 2 more answers

Calculate the phase angle (in radians) for a circuit with a maximum voltage of 12 V and w-50 Hz. The voltage source is connected

Vinvika [58]

Answer:

The phase angle is 0.0180 rad.

(c) is correct option.

Explanation:

Given that,

Voltage = 12 V

Angular velocity = 50 Hz

Capacitance $C= 20\times10^{-2}\ F$

Inductance $L=20\times10^{-3}\ H$

Resistance $R= 50\ Omega$

We need to calculate the impedance

Using formula of impedance

$z=\sqrt{R^2+(\omega L-\dfrac{1}{\omega C})^2}$

$z=\sqrt{50^2+(50\times20\times10^{-3}-\dfrac{1}{50\times20\times10^{-2}})^2}$

$z=50.00$

We need to calculate the phase angle

Using formula of phase angle

$\theta=\cos^{-1}(\dfrac{R}{z})$

$\theta=\cos^{-1}(\dfrac{50}{50.00})$

$\theta=0.0180\ rad$

Hence, The phase angle is 0.0180 rad.

3 0

4 years ago

Your question: "the picture shows a professional diver with a mass of 93 kg from a 25 m high cliff. Earths Gravity is acting on

GuDViN [60]

When we see the words "Which statement ... ", we know right away that there
will be a list of choices, and we're expected to select our answer from that list.
Strangely, the list of answer-choices for this question has been lost.

Similarly, when we see the words "The picture shows ... ", it's hard to fight
the impulse to look around. In the present situation, that's missing too.

If the diver is just standing there, then the reaction force provided by the cliff
against his feet must be exactly equal to his weight. If the vertical forces acting
on the soles of his feet were not balanced, then his feet would be accelerating
vertically.

His weight is (mass) x (gravity) =

(93 kg) x (9.8 m/s²) = 911.4 newtons (about 205 pounds) .

That's also the strength of the upward reaction force provided by the cliff.

6 0

4 years ago