Time taken for star to reach Earth = 7.5 years
<h3>Further explanation</h3>
Given
7.5 light years(distance Earth-star)
Required
Time taken
Solution
Speed of light=v = 3 x 10⁸ m/s
1 light years = 9.461 × 10¹⁵ m= distance(d)
So time taken for 1 light years :
time(t) = distance(d) : speed(v)
t = 9.461 × 10¹⁵ m : 3 x 10⁸ m/s
t = 3.154 x 10⁷ s = 1 years
So for 7.5 light years, time taken = 7.5 years
Answer:
Getting knowledge from the outside world with our senses, and scientific tools.
Explanation:
(e.g. a doctor watched a patient after giving them a. vaccine)
C+2H2 -------> CH4
from reaction 2 mol 1 mol
from the problem x mol 10 mol
x=2*10/1 = 20 mol
Answer: 20 mol of H2.
The kind of energy released when atoms are rearranged to form new bonds is called Chemical energy.