Light / Radiation. The light radiation defines its color. Thermal radiation for its temperature and the overall appearance of the wavelengths the star emits gives off the info from where astronomers and scientist are able to build up knowledge on the age and current state of the stars

5 0

3 years ago

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In an arcade game a 0.099 kg disk is shot across a frictionless horizontal surface by compressing it against a spring and releas

Sonja [21]

Answer:

The speed of disk is 1.98 $\frac{m}{s}$

Explanation:

Given:

Mass of $m = 0.099$ kg

Spring constant $k = 244 \frac{N}{m}$

Compression of spring $x = 4 \times 10^{-2}$ m

From energy conservation theorem,

Spring potential energy converted into kinetic energy,

$\frac{1}{2} m v^{2} = \frac{1}{2} k x^{2}$

$v = \sqrt{\frac{k x^{2} }{m} }$

$v = \sqrt{\frac{244 \times 16 \times 10^{-4} }{0.099} }$

$v = 1.98 \frac{m}{s}$

Therefore, the speed of disk is 1.98 $\frac{m}{s}$

8 0

3 years ago

Using Newton's Second Law, can you explain why one of the major advancements in spaceflight was the development of strong cerami

katovenus [111]

Answer:

high density can withstand high acceleration and applied forces

Heavy metals are toxic to humans,

the clay is quite abundant and in general it is not toxic

Explanation:

The selection of materials for the construction of rockets takes into account many aspects, the technical resistance to the demands of space travel, but also the abundance of the material. Heavy metals have two very serious problems. The first one, some of them are a little scarce in nature, but the most serious problem is that almost all of them are toxic to humans, for example: lead and mercury.

On the other hand, the clay is quite abundant and in general it is not toxic to living beings.

If we use Newton's second law

F = m a

let's use the concept of density

rho = m / V

m = rho V

let's substitute

F = rho V a

From this expression we see that a material with high density can withstand high acceleration and applied forces, such as those existing in spacecraft clearance and re-entry to Earth.

Unfortunately with this law there is no criterion to select a material unless its density is high, in addition to this criterion low toxicity criteria for human beings are used,

8 0

3 years ago

You throw a tennis ball straight up (neglect air resistance). It takes 7.0 seconds to go up and then return to your hand. How fa

sattari [20]

Answer:

Velocity of throwing = 34.335 m/s

Explanation:

Time taken by the tennis ball to reach maximum height, t = 0.5 x 7 = 3.5 seconds.

Let the initial velocity be u, we have acceleration due to gravity, a = -9.81 m/s² and final velocity = 0 m/s

Equation of motion result we have v = u + at

Substituting

0 = u - 9.81 x 3.5

u = 34.335 m/s

Velocity of throwing = 34.335 m/s

6 0

3 years ago