Answer:
12.495m/s
Explanation:
Horizontal displacement is the range of the projectile motion.
The range is expressed as;
R = 2U/g
U is the speed at which the rock is thrown (initial speed)
g is the acceleration due to gravity.
Given
R = 255cm = 2.55m
g = 9.8m/s²
Required
Speed U
Substitute the given parameters into the formula as shown;
2.55 = 2U/9.8
Cross multiply
2U = 2.55×9.8
2U = 24.99
U = 24.99/2
U = 12.495m/s
Hence the speed that you thew the rock is 12.495m/s
<span>When an object travels in a curved path, there must be a force acting toward the center of the circular trajectory. This force is called "centripetal force", and it cause an acceleration of the object, called "centripetal acceleration". The effect of this acceleration is that the velocity of the object changes in direction: however if the circular motion is uniform, the speed (=the magnitude of the velocity) does not change. In this case, the magnitude of the centripetal force is given by
</span>

<span>
where m is the mass of the object, v its velocity, and r the radius of the circular path.</span>
According to x-ray observations, the space between galaxies in a galaxy cluster is very hot. It is because the matter between galaxies (often called the intergalactic medium) is mostly hot, ionized hydrogen with bits of heavier elements such as carbon, oxygen and silicon thrown in.
Massive structures are collapsing than at earlier times. Large collapsing structures lead to higher velocity intergalactic shocks and, as a result, significant intergalactic shock heating, with some gas heated well above the
K temperatures.
Heating also occurs as galaxies expel out most of the gas that fell into them. The final product is a warm/hot phase, with temperatures of >
K.
Now, Let's know how do you use X-rays to make space observations?
X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites.
To learn more about Galaxy Cluster, here
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