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
Answer:
put a test tube over the opening, remove it and quickly put a lit splint near the mout or in the tube. if you hear a squeaky pop it is hydrogen.
Explanation:
hydrogen ignites in air.
Answer:
the valence electrons of atoms in a pure metal can be modeled as a sea of electrons
Answer:
The correct option is;
c. the bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
Explanation:
The most abundant metallic element found in the human body is calcium as it is present in the bones teeth and metabolism of the kidney
99 % of the calcium in the human body are found in the bones while the remaining 1 % circulates in the blood as ions
The bones of the vertebrate are made up of calcium salts such as calcium carbonate, calcium phosphate and calcium fluoride.
Answer:
The value of the partial pressure of the oxygen 
= 690 torr
Explanation:
Total pressure of the mixture of gases = 736 torr
The partial pressure of water vapor = 46 torr
From the law of pressure we know that
Total pressure = The partial pressure of water vapor + The partial pressure of oxygen 
Put the values of pressures in above equation we get,
⇒ 736 = 46 +
⇒ = 736 - 46
⇒ = 690 torr
This is the value of the partial pressure of the oxygen.
