Answer:
23.4 m/s
Explanation:
f = actual frequency of the wave = 6.2 x 10⁹ Hz
= frequency observed as the ball approach the radar
= frequency observed as the ball recede away from the radar
V = speed of light
= speed of ball
B = beat frequency = 969 Hz
frequency observed as the ball approach the radar is given as
eq-1
frequency observed as the ball recede the radar is given as
eq-2
Beat frequency is given as

Using eq-2 and eq-1

inserting the values

= 23.4 m/s
(a) The force exerted by the electric field on the electron is given by the product between the electron charge q and the intensity of the electric field E:

Under the action of this force, the electron moves by:

And the work done by the electric field on the electron is equal to the product between the magnitude of the force and the displacement of the electron. The sign has to be taken as positive, because the direction of the force is the same as the displacement of the electron, so:

(b) The electron is initially at rest and it starts to move under the action of the electric field. This means that as it moves, it acquires kinetic energy and it loses potential energy. The change in potential energy is the opposite of the work done by the electric field:

Where Uf and Ui are the final and initial potential energy of the electron.
(c) For the conservation of energy, the sum of the kinetic energy and potential energy of the electron at the beginning of the motion and at the end must be equal:

(1)
where Ki and Kf are the initial and final kinetic energies.
The electron is initially at rest, so Ki =0, and we can rewrite (1) as

and by using the mass of the electron me, we can find the value of the final velocity of the electron:
Answer:
2275000 lb.ft
Explanation:
Let work done on the cable be denoted by: W_ca
Let work done on the coal be denoted by: W_co
Now, dividing the cable into segments, let x represent the length from top of the mine shaft to the segment.
Meanwhile let δx be the length of the segment.
We are told the cable weighs 8 lb/ft. Thus;
Work done on one segment = 8 × δx × x = 8x•δx
Therefore, work done on cable is;
W_ca = ∫8x•δx between the boundaries of 0 and 650
Thus;
W_ca = 4x² between the boundaries of 0 and 650
W_ca = 4(650²) - 4(0²)
W_ca = 1,690,000 lb.ft
Workdone on the 900 lb of coal will be calculated as;
W_co = 900 × 650
W_co = 585000 lb.ft
Thus,
Total work done = W_ca + W_co
Total workdone = 1690000 + 585000
Total workdone = 1690000 + 585000
Total workdone = 2275000 lb.ft
Explanation:
Average acceleration is the change in velocity over the change in time:
a = (v − v₀) / t
In the x direction:
aₓ = (6.11 cos (-54.2°) − 5.33 cos (37.9°)) / 2.00
aₓ = -0.316 m/s²
In the y direction:
aᵧ = (6.11 sin (-54.2°) − 5.33 sin (37.9°)) / 2.00
aᵧ = -4.11 m/s²
Answer:
-55 degrees c
Explanation:
because negative numbers work in reverse and that makes -55 actually lower.