Answer:
Work done = 600 J
Power used = 60 W
Explanation:
Given:
Force acting on the box is, 
Displacement of the box is, 
Time taken for the work, 
Now, we know that, work is said to be done by a force only when there is displacement caused by the force in its direction.
Here, the force acting on the box causes a displacement of 30 m in its direction. So, work done is equal to the product of force and displacement caused.
Therefore, work done on the box is given as:
Therefore, the work done is 600 J.
Now, we know that, power is given as work done per unit time.
So, power used is given as:
Therefore, the power used is 60 W.
Answer:
pH = 5.7
Explanation:
pH = -log[H^+]
For HCl pH = -log[HCl] = - log [2.10 x 10⁻⁶ ] = 5.7
Options found from another source are:
a. oxygen. b. glucose. c. energy stored as ATP. d. carbon dioxide and water
Answer:
c energy stored as ATP
Explanation:
Cellular respiration converts glucose into energy in the form of ATP (c). The answer cannot be oxygen (a), because this is required for this process as a final electron acceptor. In terms of photosynthesis, oxygen is released as a by-product. The answer cannot be glucose (b) because that is our starting point for respiration, and what is synthesised during photosynthesis. The answer cannot be (d) as carbon dioxide and water are released by cellular respiration, and required by photosynthesis
Answer:
71.5g
Explanation:
The reaction equation is given as:
C + O₂ → CO₂
Mass of C = 42g
Mass of O₂ = 52g
Unknown:
Mass of CO₂ produced = ?
Solution
Now to solve this problem, we have to find limiting reactant which is the one given in short supply in this reaction.
The extent of the reaction is controlled by this reactant.
Find the number of moles of the given species;
Number of moles = 
Number of moles of C = 
= 3.5mol
Number of moles of O₂ = 
= 1.63mol
Now;
From the balanced reaction equation;
1 mole of C reacted with 1 mole of O₂
We see that C is in excess and O₂ is the limiting reactant.
1 mole of O₂ will produce 1 mole of CO₂
So; 1.63mole of O₂ will produce 1.63 mole of CO₂
Mass of CO₂ = number of moles x molar mass
Molar mass of CO₂ = 44g/mol
Mass of CO₂ = 1.63 x 44 = 71.5g
