Answer:
Electric field, 
Explanation:
It is given that,
Mass of sphere, m = 2.1 g = 0.0021 kg
Charge, 
We need to find the magnitude of electric field that balances the weight of a plastic spheres. So,

a = g



or

Hence, the magnitude of electric field that balances its weight is
. Hence, this is the required solution.
Answer:
lipids are insoluble in water which is why lipids are often found in biological membranes and other waterproof coverings.
Answer:
Option D: More than 90
Explanation:
Thickness probably depends on temperature. The higher the temperature, the more aliens we expect to be thin.
LASIK, or "laser-assisted in situ keratomileusis," is the most commonly performed laser eye surgery to treat myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
Like other types of refractive surgery
, the LASIK procedure reshapes the cornea to enable light entering the eye to be properly focused onto the retina for clearer vision.
In most cases, laser eye surgery is pain-free and completed within 15 minutes for both eyes. The results — improved vision without eyeglasses or contact lenses — can usually be seen in as little as 24 hours.
If you're not a good LASIK candidate, a number of other vision correction surgeries are available, such as PRK and LASEK laser eye surgery and phakic IOL surgery. Your eye doctor will determine if one of these procedures is suitable for your condition and, if so, which technique is best.