2. A 10 kg ball is rolled down a rail from a height of 20 m. What is the velocity at the bottom of the rail? Ignore friction.

19.8m/s

Explanation:

Given parameters:

Mass of the ball  = 10kg

Height of the rail  = 20m

Unknown:

Velocity at the bottom of the rail  = ?

Solution:

The velocity at the bottom of the rail is its final velocity.

Using the appropriate motion equation, we can find this parameter;

   V²   = U²  + 2gH

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

H is the height

  the ball was rolled from rest, U  = 0

  V²  = O²  + 2 x 9.8 x 20

 V  = 19.8m/s

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.