1. The change in momentum follows the formula:
Change in Momentum = mΔv,
where m is the mass and v is the velocity
Change in momentum = (700 kg)(15 m/s - 30 m/s) =<em> -10,500 kg·m/s</em>
2. For this problem, the formula for impulse, J, is
J = FΔt
Before answering part a, we answer for part b first.
Part B.
F = ma
where
a = Δv/t = (15 - 30)/5 = -1 m/s²
So,
F = (700 kg)(-1 m/s²) = <em>-700 N</em>
Part A.
J = (-700 N)(5 s) =<em> -3,500 N·s</em>
You would need to ear defenders (I'm assuming these are ear protectors for use with loud sounds) while firing at a gun range. You could use it for loud construction areas.
first object gors highest
second object goes lowest.
Answer:
Electromagnetic waves
Electromagnetic waves bring energy into a system by virtue of their electric and magnetic fields. These fields can exert forces and move charges in the system and, thus, do work on them. However, there is energy in an electromagnetic wave itself, whether it is absorbed or not.
So the answer is B electrical energy
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Answer:
It takes 28 days.
Explanation:
Hi there!
The half-life is the time at which the concentration of a substance is halved. For radon, it is 4 days. Then, after 4 days, the amount of radon present in the source will be 1/2 of its original concentration. After another 4 days, the concentration of radon will be half of the half of its original concentration, that is, 1/4 of the amount of radon originally present.
After another 4 days, the concentration will be halved again (1/4 /2 = 1/8) and after another 4 days, it will be halved again (1/8 / 2 = 1/16) and so on.
Then, after n half-lives, the concentration of radon will be reduced by a factor of 1/2ⁿ.
Then, to know how many half-lives it takes for the concentration of radon to be reduced to 1/128 of its original level, let´s solve this equation for n:
1/2ⁿ = 1/128
2ⁿ = 128
log 2ⁿ = log 128
n log 2 = log 128
n = log 128 / log 2
n = 7
After 7 half-lives, the concentration of radon will be reduced by 1/128. Since a half-life is 4 days, 7 half-lives will be (7 · 4) 28 days.