Hi,
The correct answer is C. five
I hope I helped :)
Answer:
163.33 Watts
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 40 Kg
Height (h) = 25 m
Time (t) = 1 min
Power (P) =..?
Next, we shall determine the energy. This can be obtained as follow:
Mass (m) = 40 Kg
Height (h) = 25 m
Acceleration due to gravity (g) = 9.8 m/s²
Energy (E) =?
E = mgh
E = 40 × 9.8 × 255
E = 9800 J
Finally, we shall determine the power. This can be obtained as illustrated below:
Time (t) = 1 min = 60 s
Energy (E) = 9800 J
Power (P) =?
P = E/t
P = 9800 / 60
P = 163.33 Watts
Thus, the power required is 163.33 Watts
Answer:
Option (B) is correct.
Explanation:
Given that the molecules of hydrogen gas (
) react with molecules of oxygen gas (
) in a sealed reaction chamber to produce water (
).
The governing equation for the reaction is
From the given, the only fact that can be observed that 2 moles of and 1 mole of reacts to produce 2 moles of .
As the mass of 1 mole of 
grams ... (i)
The mass of 1 mole of 
grams ...(ii)
The mass of 1 mole of 
grams (iii)
Now, the mass of the reactant = Mass of 2 moles of + mass 1 mole of
[ using equations (i) and (ii)]
grams.
Mass of the product = Mass of 2 moles of
[ using equations (iii)]
=36 grams
As the mass of reactants = mass of the product.
So, mass is conserved.
Hence, option (B) is correct.
Speed = (distance covered) / (time to cover the distance)
= ( 8.45 km) / (0.65 hr)
= (8.45 / 0.65) km/hr
= 13 km/hr
