Answer:
The magnetic field in the center of the solenoid is
.
Explanation:
Given that,
Length of solenoid = 0.425 m
Number of turns N = 950
Current I = 2.75 A
The magnetic field in the center of the solenoid is the product of the current , number of turns per unit length and permeability.
In mathematical form,

Where, 
N = number of turns
L = length
I = current
Now, The magnetic field

Put the value into the formula



Hence, The magnetic field in the center of the solenoid is
.
Answer:
330 m/s
Explanation:
The sound wave has to travel TO the cliff AND back = 2 * 49.5 = 99 m
magnitude of velocity = distance / time = 99m / .3 s = 330 m/s
1.Density of the material building the raft must be lower than the water.
<span>2. Material must not react with water. </span>
<span>3.Material must have high strength. </span>
<span>4.Raft must be wide in-order to avoid drawing in the river.</span>
Answer:
The speed at the bottom of the driveway is3.67m/s.
Explanation:
Height,h= 5sin20°= 1.71m
Potential energy PE=mgh= 2000×9.8×1.71
PE= 33516J
KE= PE- Fk ×d
0.5mv^2= 33516 - (4000×5)
0.5×2000v^2= 33516 - 20000
1000v^2= 13516
v^2= 13516/1000
v =sqrt 13.516
v =3.67m/s