We would have to search at least 5,000,000,000 (5 billion) stars before we would expect to hear a signal.
To find out the number of stars that we will need to search to find a signal, we need to use the following formula:
- total of stars/civilizations
- 500,000,000,000 (500 billion) stars / 100 civilization = 5,000,000,000 (5 billion)
This shows it is expected to find a civilization every 5 billion stars, and therefore it is necessary to search at least 5 billion stars before hearing a signal from any civilization.
Note: This question is incomplete; here is the complete question.
On average, how many stars would we have to search before we would expect to hear a signal? Assume there are 500 billion stars in the galaxy.
Assuming 100 civilizations existed.
Learn more about stars in: brainly.com/question/2166533
Answer:
6.02×10²³
Explanation:
Mole measures the number of particles in a specific substance. The numeric value of a mole for atom or molecules is approximately 6.02×10²³ atoms or molecules.
Answer:
C
Explanation:
A theory can be changed when new evidence is found. A law doesn't change because it is universally a fact. It doesn't need new evidence to support it.
Answer:
The speed is 
and the direction is heading north.
Explanation:
In collisions the force exerted by the objects that collide is higher enough than the external forces that we can neglect that external forces, with that assumption we can use the conservation fo momentum law that states, final total momentum (pf) is equal initial total momentum (pi) if there’re not external forces or they are small enough to be neglected. Mathematically:
The total momentum is the sum of the momentum of each of the bodies we're dealing, in our case the moment of each car, then:
with pn the momentum of the 1000kg car heading north and ps the 800kg car heading south. Momentum is defined as mass times velocity, then:
(1)
It's important to note that when we talk about momentum and velocity direction matters, so we're are going to choose a system of reference where quantities pointing north are positive and pointing south are negative. So, the initial velocity of 1000 kg car is vni=5 m/s, initial velocity of 800 kg car is vsi=-4 m/s and the final velocity of 1000 kg car is vnf=-1 m/s. Now we can solve (1) for vsf and use the values we already have:
Because the sign is positive the direction is to heading north.
"The path difference between the two waves should be one-quarter of a wavelength" is the statement among the choices given in the question that describes the <span>path difference between the two waves. The correct option among all the options that are given in the question is the fifth statement or the penultimate statement.</span>
