What defines our current ‘standard' for one meter? A The distance equal to 1/10,000,000 the distance between the Equator and North Pole b The length of a pendulum arm that takes 1 second to swing from left to right c The distance a 1 kilogram object travels in one second when acted on by a force of 1 newton d The distance light travels in a tiny fraction of a second

The distance light travels in a tiny fraction of a second

Explanation:

One meter is defined as the length of the path travelled by light in a vacuum in of a second. It is also equal to the one of the distance from the equator to the North Pole. It is one of the fundamental units. It is a SI unit of length. So, the standard definition of 1 mete is the distance light travels in a tiny fraction of a second.

Hence, the correct option is (d).

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied