Answer:
vDP = 21.7454 m/s
θ = 200.3693°
Explanation:
Given
vDE = 7.5 m/s
vPE = 20.2 m/s
Required: vDP
Assume that
vDE to be in direction of - j
vPE to be in direction of i
According to relative motion concept the velocity vDP is given by
vDP = vDE - vPE (I)
Substitute in (I) to get that
vDP = - 7.5 j - 20.2 i
The magnitude of vDP is given by
vDP = √((- 7.5)²+(- 20.2)²) m/s = 21.7454 m/s
θ = Arctan (- 7.5/- 20.2) = 20.3693°
θ is in 3rd quadrant so add 180°
θ = 20.3693° + 180° = 200.3693°
Average Velocity = Total Displacement / Total time
1st part of journey, 350 km at velocity 125 km/h
Time = 350 / 125 = 2.8 hours.
2nd part of journey, 220 km at velocity 115 km/h
Time = 220 / 115 = 1.9 hours
Average Velocity = Total Displacement / Total time
= (350 + 220) / (2.8 + 1.9)
= 570 / 4.7 ≈ 121.3 km/hr
Average Velocity ≈ 121 km/hr due south.
Option C.
Explanation:
Relation between potential energy and charge is as follows.
U = qV
or, 
= 
= 
J
or, = 
Therefore, we can conclude that change in the electrical potential energy 
is .
The correct answer Is B-balanced
Answer:
a) V = 195.70 m/s
b) f=3.02 × 10⁻⁴ Hz
c) T = 3311.25 seconds
Explanation:
Given:
Wavelength, λ = 646 Km = 646000 m
Distance traveled = 3410 Km = 3410000 m
Time = 4.84 h = 4.84 × 3600 s = 17424 seconds
a) The speed (V) of the wave is given as
V = distance / time
V = 3410000 m/ 17424 seconds
or
V = 195.70 m/s
b) The frequency (f) of the wave is given as:
f = V / λ
f= 195.70 / 646000
f=3.02 × 10⁻⁴ Hz
c) The time period (T) is given as:
T = 1/ f
T = 1/ (3.02 × 10⁻⁴) Hz
T = 3311.25 seconds
