One electron Volt (eV) is equal to 1.6 x 10^-19 Joules. Therefore, 10 eV is equal to 1.6 x 10^-18 Joules. In order to produce 20 Joules of energy from 10 eV photons, we would require 20 x 1/(1.6 x 10^-18) = 1.25 x 10^19 particles. This demonstrates that in the world of particle physics, the Joule is a massive energy unit relative to the commonly used electron Volt.
The sprinter’s average acceleration is 1.98 m/s²
The given parameters;
- initial velocity of the sprinter, u = 18 km/h
- final velocity of the sprinter, v = 27 km/h
- time of motion of the sprinter, t = 3.5 x 10⁻⁴ h
Convert the velocity of the sprinter to m/s;

The time of motion is seconds;

The sprinter’s average acceleration is calculated as follows;

Thus, the sprinter’s average acceleration is 1.98 m/s²
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A.is an example of decomposition reaction.
Answer:
Depending on the relative position of the Earth the Sun and Neptune in the Earths orbit the distances are;
The closest (minimum) distance of Neptune from the Earth is 29 AU
The farthest (maximum) distance of Neptune fro the Earth is 31 AU
Explanation:
The following parameters are given;
The distance from the Earth to the Sun = 1 AU
The distance of Neptune from the Earth = 30 AU
We have;
When the Sun is between the Earth and Neptune, the distance is found by the relation;
Distance from the Earth to Neptune = 30 + 1 = 31 AU
When the Earth is between the Sun and Neptune, the distance is found by the relation;
Distance from the Earth to Neptune = 30 - 1 = 29 AU
Therefore, the closest distance from Neptune to the Earth in the Earth's Orbit is 29 AU
The farthest distance from Neptune to the Earth in the Earth's orbit is 31 AU.
Answer:
1. Recollapsing universe
2. Critical universe
3. Coasting universe
Explanation:
Recollapsing universe has dark matter density greater than critical density. While critical universe has its matter density equal to the critical sensity. Coasting universe on the other hand has much smaller matter density compared to critical density.
Note that the critical density is approximately 10^-20 grams/cm3