Answer: 20.4752789138x x 10^23 atoms
To count how many atoms in moles you need to know Avogadro's number. Avogadro's number dictate that for every mole there is 6.022140857 × 10^23 molecule/atoms.
Then 3.4 moles of helium will be 3.4x 6.022140857 x 10^23 atoms= 20.4752789138x x 10^23 atoms
Answer:
A. The waves in the water travel faster and at a higher frequency than they travel on land.
Explanation:
The main reason why human ears can hear dolphins' vocalizations while under the water but cannot hear them well on land is because water is denser than air and air particles travel faster in denser particles.
Denser particles also ensures that the frequency of the waves move faster which in turn produces a faster and louder result.
Answer: 62 μT
Explanation:
Given
Length of rod, l = 1.33 m
Velocity of rod, v = 3.19 m/s
Induced emf, e = 0.263*10^-3 V
Using Faraday's law, the induced emf of a rod can be gotten by the formula
e = blv where,
e = induced emf of the rod
b = magnetic field of the rod
l = length of the rod
v = velocity of the rod. On substituting, we have
0.263*10^-3 = b * 1.33 * 3.19
0.263*10^-3 = b * 4.2427
b = 0.263*10^-3 / 4.2427
b = 0.0000620 T
b = 62 μT
Thus, the strength of the magnetic field is 62 μT
Answer:
Explanation:
Since this is a distance v time graph, the slope of the line from 1s to 3s is the velocity. However, it looks like, at t=3, the velocity is 0, so getting the definite velocity is not going to happen. We can estimate it as closely as possible. Since the line is tending from the upper left to the lower right, the slope is negative, so the velocity is also negative. That leaves only C or D as our answers. And the slope is closer to -1 than to -5, so choice D. is the one you want.
Answer:
18 m/s
Explanation:
Given that,
Speed of river is 8 m/s due South
From the shore, you see a boat moving South with a speed of 10 m/s. Both boat and river are moving in same direction. The resultant velocity will add up.
v = 10 m/s + 8 m/s
v = 18 m/s
Hence, the rowers are moving with a speed of 18 m/s.
