Answer:
Sonar
Explanation:
Sonar is a technique that involves the use of sounds in viewing substances in a water medium to aid movement or communication. It makes use of the advantage of sound waves traveling faster and farther in water when compared to other types of waves such as light waves.
During World War II, the military employed the use of SONAR in imaging the seafloor by sending pulses of sound waves down through the water and measuring the time it took for the sound to bounce off the seafloor and return to the receiver.
7.5 I think because it can not be 9 because it’s not close to 50
Answer:
50 kg
Explanation:
Given,
Force ( F ) = 100 N
Acceleration ( a ) = 2 m/s^2
To find : Mass ( m ) = ?
Formula : -
F = ma
m = F / a
= 100 / 2
m = 50 kg
Therefore, the mass of the object is 50 kg.
Answer:
t = 5.59x10⁴ y
Explanation:
To calculate the time for the ¹⁴C drops to 1.02 decays/h, we need to use the next equation:
(1)
<em>where
: is the number of decays with time, A₀: is the initial activity, λ: is the decay constant and t: is the time.</em>
To find A₀ we can use the following equation:
(2)
<em>where N₀: is the initial number of particles of ¹⁴C in the 1.03g of the trees carbon </em>
From equation (2), the N₀ of the ¹⁴C in the trees carbon can be calculated as follows:
<em>where
: is the tree's carbon mass,
: is the Avogadro's number and
: is the ¹²C mass. </em>
Similarly, from equation (2) λ is:
<em>where t 1/2: is the half-life of ¹⁴C= 5700 years </em>

So, the initial activity A₀ is:
Finally, we can calculate the time from equation (1):
I hope it helps you!