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
Physical change because it's only changing the shape of the gold.
Answer:Radium
Explanation:
The nuclear reaction involving two alpha emissions of 234 U is shown in the diagram. This leads to the formation of a 226Ra nucleus.
Answer:-
2747.7 Cal mol -1
Explanation:-
Molar heat of Fusion is defined as the amount of heat necessary to melt (or freeze) 1 mole of a substance at its melting point.
Atomic mass of Iron = 55.845 g mol-1
Mass of Iron = 200 g
Number of moles of Iron = 200 g / (55.845 g mol-)
= 3.581 moles
Heat released = 9840 Cal
Molar heat of Fusion = Heat released / Number of moles
= 9840 Cal / 3.581 moles
= 2747.7 Cal mol -1
Plant: leaf tissue
Human: lungs
