Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
Given: Mass m = 44 Kg; Velocity v = 10 m/s
Required: Kinetic energy K.E = ?
Formula: K.E = 1/2 mv²
K.E 1/2 (44 Kg)(10 m/s)²
K.E = 2,200 Kg.m²/s²
K.E = 2,200 J Answer is A
<h3><u>Answer;</u></h3>
- A moving electric charge creates a magnetic field at all points in the surrounding region.
- An electric current in a conductor creates a magnetic field at all points in the surrounding region.
- A permanent magnet creates a magnetic field at all points in the surrounding region.
<h3><u>Explanation;</u></h3>
- A magnetic field can be created by running electricity through a wire. All magnetic fields are created by moving charged particles. it is important to also note that charged particles create magnetic fields only when they are moving.
- The strength of the magnetic field generated or created is proportional to the amount of current flowing through the wire. Thus, increasing the current increases the strength of the magnetic field.
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
To learn more about focal length go to - brainly.com/question/25779311
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