Answer:
Yes
Explanation:
The core of an electromagnet serves to stabilize the magnetic field created by the wire. The thicker the core, the more metal there is to amplify the current. Therefore, a thicker core does make an electromagnet stronger. Hope this helps!
Volume= Length X width X height.
Plug in the values for each and solve for the volume.
V= (L)(W)(H)
V=(4cm)(5cm)(10cm).
Answer:
147.7 N
221.55 Nm
Explanation:
P = Pressure = 100000 Pa
= Mass-specific gas constant = 287.015 J/kg k
T = Temperature = 10+273 = 283 K
C = Drag coefficient = 1.1
A = Area
r = Radius = 0.2 m
v = Speed of wind = 
L = Length of pole
Density

Drag force

Force on the circular sign is 147.7 N

Bending moment at the bottom of the pole is 221.55 Nm
Answer:
0.25A
1.0A
2.5A
Explanation:
this is only for the calculated current column on edge
Answer:
t ’=
, v_r = 1 m/s t ’= 547.19 s
Explanation:
This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.
By the time the boat goes up the river
v_b - v_r = d / t
By the time the boat goes down the river
v_b + v_r = d '/ t'
let's subtract the equations
2 v_r = d ’/ t’ - d / t
d ’/ t’ = 2v_r + d / t
In the exercise they tell us
d = 1.22 +1.45 = 2.67 km= 2.67 10³ m
d ’= 1.45 km= 1.45 1.³ m
at time t = 69.1 min (60 s / 1min) = 4146 s
the speed of river is v_r
t ’=
t ’=
In order to complete the calculation, we must assume a river speed
v_r = 1 m / s
let's calculate
t ’=
t ’= 547.19 s