Electromagnets are devices that create a magnetic field through the application of electricity. Strong electromagnets are used to lift, move and drop heavy objects, such as vehicles. Electromagnets have advantages over permanent magnets. When the current is switched off, the electromagnet will lose its magnetism. The car will fall back to earth and we need that when we move cars in a junkyard. With a regular ( permanent ) magnet it would be much harder to do.
Answer: A. True
<span>Justification
Step 1: Let a = b.
Step 2: Then a^2 = ab ,
Step 3: a^2 + a^2 = a^2 + ab ,
Step 4: 2a^2=a^2 + ab,
Step 5: 2a^2 - 2ab = a^2 + ab - 2ab,
Step 6: and 2a^2 - 2a^b = a^2 + ab - 2ab .
Step 7: This can be written as 2(a^2 - ab) = 1(a^2 - ab) ,
Step 8: and cancelling the (a^2 - ab) from both sides gives 1 = 2.</span>
The formula for volume of a cone is V=(1/3)*h*π*(r^2)
our height is 7.5 feet, and since the length of the base of the cone (diameter) is 22 feet long, the radius is 11 feet long.
(1/3)*7.5*π*(11^2)=302.5*π=950.3
so the volume of the house is about 950 feet cubed.
