Can permanently damage skin

We can always determine the recession velocity of a galaxy (at least in principle) from its redshift. but before we can use hubb

pychu [463]

Measuring the distance to many distant galaxy with a standard candle technique.

Hubble presented the observational evidence for one of science’s greatest discoveries—the expanding universe. Hubble showed that galaxies are receding away from us with a velocity that is proportional to their distance from us: more distant galaxies recede faster than nearby galaxies.

A redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation.

The standard candle technique is particularly valuable when studying very distant objects. Eventually, the effects of parallax stop working because things get too far away. However, since a standard candle depends on the inverse square law, it can reach much further as a result.

As long as we have instruments that can detect a standard candle and measure its brightness, it can be used to measure a distance.

therefore before measuring the recission velocity one must use standard candle technique to eliminate any parallax

learn more about parallax here:

brainly.com/question/1394541

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2 years ago

A 75.0kg bicyclist (including the bicycle) is pedaling to the right, causing her speed to increase at a rate of 2.20m/s^2, despi

aniked [119]

1) 4 forces

2) 165 N

3) 225 N

Explanation:

1)

There are in total 4 forces acting on the bicylist:

- The gravitational force on the byciclist, acting vertically downward, of magnitude $mg$ , where m is the mass of the bicyclist and g is the acceleration due to gravity

- The normal force exerted by the floor on the bicyclist and the bike, N, vertically upward, and of same magnitude as the gravitational force

- The force of push F, acting horizontally forward, given by the push exerted by the bicylist on the pedals

- The air drag, R, of magnitude R = 60.0 N, acting horizontally backward, in the direction opposite to the motion of the bicyclist

2)

The magnitude of the net force on the bicyclist can be calculated by considering separately the two directions.

- Along the vertical direction, we have the gravitational force (downward) and the normal force (upward); these two forces are equal in magnitude, since the acceleration of the bicyclist along this direction is zero, therefore the net force in this direction is zero.

- Along the horizontal direction, the two forces (forward force of push and air drag) are balanced, since the acceleration is non-zero, so we can use Newton's second law of motion to find the net force on the bicylist:

$F_{net}=ma$