Answer:
Q = 270 Joules (2 sig. figs. as based on temperature change.)
Explanation:
Heat Transfer Equation of pure condensed phase substance => Q = mcΔT
Mixed phase (s ⇄ l melting/freezing, or l ⇄ g boiling/condensation) heat transfer equation => Q = m∙ΔHₓ; ΔHₓ = phase transition constant
Since this is a pure condensed phase (or, single phase) form of lead (Pb°(s)) and not melting/freezing or boiling/condensation, one should use
Q = m·c·ΔT
m = mass of lead = 35.0g
c = specific heat of lead = 0.16J/g°C
ΔT = Temp change = 74°C - 25°C = 49°C
Q = (35.0g)(0.16J/g·°C )(49°C) = 274.4 Joules ≅ 270 Joules (2 sig. figs. as based on temperature change.)
Answer:
Newton's Second Law
Explanation:
Newton's second law basically states that the acceleration of a body which is produced by a net force is directly proportional to the magnitude of net force applied in the same direction.
This tells us that
F is directly proportional to a
⇒ F= ma
So we can also state from the above equation, that when we have more mass, we need more net force to accelerate it. Here, we are keeping the acceleration constant so we can surely say that force and mass varies directly.
Therefore, we have made good use of Newton's Second Law of motion to arrive at this conclusion.
Answer:
Exchange across cell membranes - diffusion. The higher the concentration gradient, the faster the rate of facilitated diffusion, up to a point. As equilibrium is reached the concentration gradient is much lower because the difference in concentrations is very small so the rate of facilitated diffusion will slow down and level off.
Explanation:
First one is reactants and then second one is products