Explanation:
Write in scientific notation.
4000 = 4.0×10³
Answer:

Explanation:
Mass and weight ain't the same thing. So, for calculating weight we would use Newton's 2nd Law of Motion i.e. Force = Mass × Acceleration.
According to question,
The mass is 20kg
Acceleration is 9.8 m/s^2
Putting the given values into the formula,
F = 20 × 9.8
F = 196N
So, the weight of the rock is 196 N
Hope it helps!<3
Its thin glass fibers that let light be transmitted through them
Answer:
interstellar gas clouds may collapse to from a star if they [ecounter a shock wave.]