Answer:
Energy is found as:
E = 1.987·10⁻¹⁹ J
Explanation:
Energy of a single photon of infrared light can be found by using the following formula:
where
E = in Joules
h = Planck's constant = 6.627×10 ⁻³⁴ J
f = frequency in hertz
It can also be written as:
where
c = 2.998×10⁸ ms⁻¹
λ = wavelength
Wavelength is given in the question which is:
λ = 1×10⁻⁶m
Substitute all the values in the Energy formula
The answer to this question i think would be 8950. Do you have any answer choices.
Answer:
A. Speed is a scalar quantity and velocity is a vector quantity.
Explanation:
A scalar quantity is one that consists of only a numerical value.
Speed is a scalar quantity because only the instantaneous value is indicated, for example the speedometer of a car that tells you your speed at the moment but not where you are going or in what direction are you going.
On the other hand, velocity is a vector quantity. Because it is composed of a <u>magnitude and a direction</u>, for example 10m/s to the south is a velocity, and 10m/s is a speed.
Before going to answer this question first we have to know the fundamental principle of magnetism.
A magnet have two poles .The important characteristic of a magnet is that like poles will repel each other while unlike poles will attract each other.
Through this concept the question can be answered as explained below-
A-As per first option the side of magnet A is repelled by the south pole of magnet B. Hence the pole of a must be south .It can't be north as it will lead to attraction.
B-The side of magnet A is repelled by the north pole of magnet B. Hence the side of A must be north pole.It can't be a south pole.
C-The side of magnet A is attracted by the south pole of magnet B .Hence the side of magnet A must be north.Hence this is right
D-The side of magnet A is attracted by the north pole of magnet B. Hence the side of A must south.It can't be north as it will lead to repulsion.
Hence the option C is right.
Answer:
1)a. It is constant the whole time the ball is in free-fall.
2)b. = 14 m/s
3) e. = 19.6 m/s
Explanation:
1) given that the only force acting on the ball is gravity, gravity acts along the vertical axis. Since no other force acts on the ball then the horizontal velocity will remain constant all through the flight since there is no horizontal force acting on the ball.
2) speed = distance/time
horizontal distance = 56m
Time = 4 seconds
Speed = 56m/4s = 14m/s
3) acceleration due to gravity g = 9.8m/s^2
Initial vertical velocity = u
Final vertical velocity = v = -u
Using the law of motion;
v = u + at
a = acceleration = -g = -9.8m/s^2
t = time of flight = 4
Substituting the values;
-u = u - 4(9.8)
-2u = -4(9.8)
u = -4(9.8)/-2
u = 2(9.8) = 19.6 m/s
Initial vertical velocity = u = 19.6 m/s
