Answer:
A. It makes astronauts weightless.
Explanation:
Gravity does not make astronauts feel weightless. Astronauts are weightless because they are orbiting at the same rate as their shuttle.
Although the force of gravity weakens as one moves away from the earth surface, it does not mean that this force is absent in orbit
- Gravitational force has a constant acceleration value near the earth surface which is commonly known to be 9.8m/s².
- It is a force of attraction tending to hold and bind bodies together so far they have mass.
- This force keeps every thing from escaping space-ward from the earth surface.
<span>This question is based on conservation of energy as the work done would lead to change in kinetice energy of car
change in KE = 1/2 mv(f)^2 - 1/2mv(i)^2 = 1/2m(v(f)^2-v(i)^2)
where v(f) and v(i) are the final and initial speeds
change in KE = 185kJ = 185,000J = 1/2 m((28m/s)^2-(23m/s)^2)
185,000=1/2 m(255m^2/s^2)
solving for m
m=1451kg</span>
Because if they were in the inside, then they would not be able to sexually reproduct and could not have offspring.
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!
