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!
Answer:
<em>The average speed is 22.2 km/h</em>
Explanation:
<u>Average Speed</u>
Given an object travels a total distance d and took a total time t, then the average speed is:

The mailman first drives d1=7 km at v1=15 km/h. The time taken to drive is:

Then he drives d2=7 km at v2=43 km/h taking a time of:

The total time is
t=0.467 h + 0.163 h = 0.63 h
The total distance is
d = 7 km + 7 km = 14 km
The average speed is:

The average speed is 22.2 km/h
The SI unit of time is second
Answer:
.
Explanation:
The efficiency of a machine is the percentage of energy input that was turned into useful energy.
The power rating of this lamp is
(same as
,) meaning that
of energy is supplied to this lamp every second.
The question states that
out of that
of energy input would be turned into heat, which is not useful energy output in this scenario. Assuming that all other forms of energy loss is negligible. The rest of the
of energy supplied to this lamp would be turned into useful energy output.
Thus, every second, this lamp would receive
of energy input and would outputs
of useful work. The efficiency of this lamp would be:
.