Answer:
v = 1.5 m/s
Explanation:
Given that,
Distance covered by a person, d = 105 m
Time taken, t = 70 s
We need to find the average speed of the person. We know that the average speed is given by :
So, the average speed of the person is equal to 1.5 m/s.
Answer:
726 torr
Explanation:
Generally, atmospheric pressure can be measured using a manometer which is in form of a U-shaped tube. In addition, 1 mm Hg is equivalent to 1 torr. Therefore, 752 torr is equivalent to 752 mm Hg. Therefore, the total pressure will be equivalent to the atmospheric pressure (mm Hg) + the mercury height.
In this case, the mercury height = -26 mm
Thus:
The helium pressure = 752 - 26 = 726 mm Hg
This is also equivalent to 726 torr
Since the density of water is 1 g /mL, hence there is 100
g of H2O. So total mass is:
m = 100 g + 5 g = 105 g
=> The heat of reaction can be calculated using the
formula:
δhrxn = m C ΔT
where m is mass, C is heap capacity and ΔT is change in
temperature = negative since there is a decrease
δhrxn = 105 g * 4.18 J/g°C * (-2.30°C)
δhrxn = -1,009.47 J
=> However this is still in units of J, so calculate
the number of moles of NaCl.
moles NaCl = 5 g / (58.44 g / mol)
moles NaCl = 0.0856 mol
=> So the heat of reaction per mole is:
δhrxn = -1,009.47 J / 0.0856 mol
δhrxn = -11,798.69 J/mol = -11.8 kJ/mol
The density of an object or quantity of matter is its mass divided by its volume.
