Answer:
8 m west
Explanation:
If we say east is the +x direction, and west is the -x direction, then the displacement is:
Δx = 12 m + (-20 m)
Δx = -8 m
Answer:
993.52 Hz
Explanation:
The frequency of sound emitted by the stationery train is 1057 Hz.
The car travels away from the train at 20.6 m/s.
The frequency the observer hears is given by the formula:

where v = velocity of sound = 343 m/s
vo = velocity of observer
f = frequency from source
This phenomenon is known as Doppler's effect.
Therefore:

The frequency heard by the observer is 993.52 Hz.
Answer
given,
Echo time = t = 1000 s
speed = ?

a) speed of electromagnetic wave

wave travels Venus two time



d = 1.5 x 10¹¹ m
b) now, echo time



t = 5 x 10⁻⁷ s
Wouldn’t it be 1. resistance is high compared to the voltage and with less resistance, higher current