If energy could<span> be created or </span>destroyed<span>, all of our ideas of how the world works ... Historically, of course </span>not<span> all the forms of energy were known to begin with. ... too messy or complicated to make sense, we </span>would have<span> had to give up the law. ... </span>can<span> be converted into rest </span>mass<span> and back again (particle physicists </span>do<span> this </span><span>every )</span>
<u>Answer</u>
1 1/3 m/s
<u>Explanation</u>
The momentum before collision and after collision is always conserved.
m₁v₁ = m₂v₂
(0.05×0.6) + (0.03×0) = (0.03 × v) + (0.05 × -0.2)
0.03 + 0 = 0.03v - 0.01
0.03v = 0.03+0.01
0.03v = 0.04
v = 0.04/0.03
= 4/3
= 1 1/3 m/s
With mass 2500 kg, the elevator has weight
(2500 kg) <em>g</em> = (2500 kg) (9.80 m/s²) = 24,500 N
The net force on the elevator is 30,000 N - 24,500 N = 5500 N (because its weight pulls it downward, while the tension pulls upward).
The acceleration <em>a</em> of the elevator is obtained from Newton's second law,
(2500 kg) <em>a</em> = 5500 N
<em>a</em> = (5500 N) / (2500 kg)
<em>a</em> = 2.2 m/s²
Answer:
Solids
Explanation:
Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
