Answer:
Boron (B) Atomic Mass: 10.811
Explanation:
The number of protons and electrons are the same, always. You can find the atomic mass by looking at the periodic table for that atom: 10.811
A) -0.5(9.8)*t^2 = -25(t-2) - 0.5(9.8)(t-2)^2
-4.9t^2 = -25t + 50 - 4.9(t^2-4t+4)
0 = -25t+50+19.6t - 19.6
5.4t = 30.4
t = 5.62962963 s
b) h = -4.9(5.62962963)^2
h = -155.2943759
the building is 155.2943759 m high
c) speed 0of first stone
= at
= 9.8*5.62962963
= 55.17037037 m/s
speed of second stone
= v + at
= 25+9.8*3.62962963
= 60.57037037 m/s
False , it will make it lighter
I think its the mirror because condenser helps in allowing the amount of light to pass.