Why is the depletion of hydrogen in the core of a star such an important event?
1 answer:
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Answer:
0.35 kg
Explanation:
8 cm = 0.08 m
For the block to stay balance, the buoyancy force must be the same as gravity that pulls it down.
Let mass of the block be M, then the gravity would be Mg
Let water density be , the buoyancy force would be the weight of water that is displaced by the submerged block.
For example, when there is no coin, block is submerged. The weight of water displaced must be
Which is also the weight of block, of Mg
Therefore M = 31.2A. (1)
As coins are stacked on top of block, h increase, so as weight of water displaced and total weight of block and coins. Now let m be the total weight of coins. The gravity of block and weight must be (M+m)g. And the weight of water displaced is:
Since the linear plot of h vs m has a slope of 0.089 m/kg, we can interpret it as
So from the eq. (1) we can solve for M = 31.2A = 0.35 kg
Answer:
The energy of one photon is 2.21x10⁻²⁴ J. Multiplied by 10²⁵ is 22.10 J.
Explanation:
The energy (E) of a photon is:
Where:
h: is the Planck's constant = 6.62x10⁻³⁴ J.s
λ: is the wavelength of the radiation = 8.97 cm
c: is the speed of light = 3.00x10⁸ m/s
Hence, the energy of one photon is 2.21x10⁻²⁴ J.
Now, if we multiply the answer by 10²⁵ we have:
I hope it helps you!
Answer:
ΔT = 59.9 ° C
Explanation:
For this exercise the brake energy is totally converted into heat
Let's calculate the vehicle energy
K = ½ m v²
Let's reduce the units to the SI system
v = 30 mph (1609.34 m / mile) (1h / 3600s) = 13.41 m / s
Em = K = ½ 1200 13.41²
K = 1.079 105 J
All this energy is transformed into heat
Em = Q
The expression for heat is
Q = m ΔT
ΔT = Q / m
The specific heat of iron is = 450 J / Kg ºC
ΔT = 1,079 105 / (4.0 450)
ΔT = 59.9 ° C