Answer:
4.42 x 10⁷ W/m²
Explanation:
A = energy absorbed = 500 J
η = efficiency = 0.90
E = Total energy
Total energy is given as
E = A/η
E = 500/0.90
E = 555.55 J
t = time = 4.00 s
Power of the beam is given as
P = E /t
P = 555.55/4.00
P = 138.88 Watt
d = diameter of the circular spot = 2.00 mm = 2 x 10⁻³ m
Area of the circular spot is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
Intensity of the beam is given as
I = P /A
I = 138.88 / (3.14 x 10⁻⁶)
I = 4.42 x 10⁷ W/m²
Answer:
0.426 L
Explanation:
Boyles law is expressed as p1v1=p2v2 where
P1 is first pressure, v1 is first volume
P2 is second pressure, v2 is second volume.
Given information
P1=96 kPa, v1=0.45 l
P2=101.3 kpa
Unknown is v2
Making v2 the subject from Boyle's law
Substituting the given values then
Therefore, the volume is approximately 0.426 L
Answer:
D. Sounds would be harder to hear.
Explanation:
if the ear canal is blocked then the sound waves cannot reach the ear drum thus we cannot hear clearly.
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Explanation:
Activation energy and reaction rate
The activation energy of a chemical reaction is closely related to its rate. Specifically, the higher the activation energy, the slower the chemical reaction will be. ... The released energy helps other fuel molecules get over the energy barrier as well, leading to a chain reaction.
29.213 cm3
First, calculate the mass of the water used. You do this by subtracting the original mass of the flask from the combined mass of the water and flask, giving:60.735 g - 31.601 g = 29.134 g
So we now know we have 29.134 g of water. To calculate the volume of the flask, simply divide by the density of the water, giving:29.134 g / (0.9973 g/cm3) = 29.213 cm3
