Answer:
momentum in a body can be calculated using
<em><u>Mome</u></em><em><u>ntum</u></em><em><u>=</u></em><em><u>Mass×</u></em><em><u>V</u></em><em><u>e</u></em><em><u>l</u></em><em><u>o</u></em><em><u>s</u></em><em><u>i</u></em><em><u>t</u></em><em><u>y</u></em><em><u> </u></em>
<em><u>i</u></em><em><u>e(</u></em><em><u>p</u></em><em><u>=</u></em><em><u>m×</u></em><em><u>v</u></em><em><u>)</u></em>
Answer:
500 m/s
Explanation:
Momentum, p is a product of mass and velocity. From law of conservation of momentum, the initial momentum equals final momentum

Here m and v represent mass and velocity respectively and subscripts 1 and 2 represent car and barrier respectively
Therefore, the velocity of barrier will be 500 m/s
To work out kinetic energy, we use the following formula: KE = 0.5 x mv^2. So, 0.5 x 4 x 16^2 = 512 J
<span>The distance between two objects is increased by three times the oringinal distance. Since they were already separated by one time the original distance,
the additional three times the oringinal distance now puts them four times the original distance apart.
Whether we're talking about the gravitational forces of attraction or
the electrical forces of attraction, either one is inversely proportional
to the square of the distance between the objects.
So changing the distance to four times the original distance causes
the forces to become 1/4</span>² as strong as they were originally.
The forces become 1/16 of their original magnitude.<span>
</span>
The Sun is a huge, glowing sphere of hot gas. Most of this gas is hydrogen (about 70%) and helium (about 28%). Carbon, nitrogen and oxygen make up 1.5% and the other 0.5% is made up of small amounts of many other elements such as neon, iron, silicon, magnesium and sulfur.
So typically I would say hydrogen and helium.