Answer:
Velocity (v) is a vector quantity that measures displacement (or change in position, Δs) over the change in time (Δt), represented by the equation v = Δs/Δt. Speed (or rate, r) is a scalar quantity that measures the distance traveled (d) over the change in time (Δt), represented by the equation r = d/Δt.
Explanation:
Answer:
B. The number of electrons emitted from the metal per second increases.
Explanation:
Light consists of photons . Energy of each photon depends upon frequency of light . The increase in intensity increases the number of photons . It does not increase energy of photons .
So if a high intensity light falls on a photosensitive plate , each photon ejects one electron . So number of electrons increases if we increase intensity of photon. It does not increase kinetic energy of ejected electrons . Work function depends upon the nature of plate.
In order to make any headway with this one, it might help
to know how many joules there are in one BTU, ya reckon ?
I went and looked it up on line, you're welcome.
1 BTU = 1055.06 joules .
So if you happen to have 1,152 BTU of energy,
there are 1055.06 joules in each one of them,
and the total is
(1,152 BTU) x (1,055.06 joule/BTU)
= 1,215,429.12 joules .
Scanning the choices for anything close, we notice that choice-'b'
is only about 0.006% less than my answer. So that must be the one
they're fishing for, and they must have used 1055-even for their
conversion factor.
The kinetic energy of the bullet is 20.4 kJ.
<u>Explanation:</u>
Kinetic energy of a bullet will be equal to the product of mass of the bullet with the square of velocity or speed of the bullet and then the half of that product value.
But here the mass of the bullet is not given, instead the weight of the bullet is given in terms of force. So from this, we have to first find the mass of the bullet.
We know that as per Newton's second law of motion, force is directly proportional to the product of mass and acceleration. So here the acceleration will be equal to the acceleration due to gravity as it is weight of the object.
So F = mg
0.10 N = m × 9.8
So ,the mass of the bullet is 0.0102 kg.
Now, we know the mass and velocity of the bullet is given as 2000 m/s.
So,
kinetic energy =
× m × v²
kinetic energy = 0.5 × 0.0102 × 2000 × 2000 = 20.4 kJ
Thus, the kinetic energy of the bullet is 20.4 kJ.