The specific answer for that will be 71.38 kg
Explanation:
When the wire is connected to a battery, the compass needle moves and changes its position. This happens because the needle magnetizes the copper wire, thus, creating a force.
While the current in the wire produces a magnetic field and exerts a force on the needle. The insulation on the wire becomes energized and exerts a force on the needle. Hence, the compass needle moves and changes its position.
if rebecca stands in front of david at a distance of do and david perceives the position of rebecca at di, di will be +84 cm
<h3>What is focal length ?</h3>
How strongly light converges or diverges depends on an optical system's focal length, which is the inverse of optical power. A system with a positive focus length is said to converge light, whereas one with a negative focal length is said to diverge light.
focal length = +60 cm
magnification m = -0.40
focal length being positive an magnification negative.
given lens is a convex lens.
for a lens
m = di/do and 1/f = (1/di) - (1/do)di
= -0.4do1/f = (1/-0.4do) - 1/do do
= -210 cmdi = -0.4 * -210
di = +84 cm
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