Answer:
Explanation:
distance of fan A = 18.3 m
distance of fan B = 127 m
speed of sound (s) = 343 m/s
What is the time difference between hearing the sound at the two locations?
time (T) = distance / speed
- time for sound to reach fan A = 18.3 / 343 = 0.053 s
- time it takes for sound to reach fan B = 127 / 343 = 0.370 s
- time difference = 0.370 - 0.053 = 0.317 s
Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
Answer
NB:
- speed, U is measure in m/s
- acceleration, a is measured in m/s²
-time t in seconds , s
Therefore conversation must be made
Speed U = 20km/hrs
=20km÷1hr
But 20km= 20×1000=20000m
1hr= 1×60min×60sec=3600s
U=20000÷3600=5.56m/s
a=30km/hrs
=30km÷1hr
But 30km=30×1000=30000
1hr=3600s
a=30000÷3600=8.33m/s²
From the equation of motion
S=Ut + ½ at².
Where s= distance
S = 5.56m/s × 20s + ½(8.33m/s²)(20s)²
S = 1777.3m
I think it’s true because drugs ruin your system :/