Why do black holes have a massive force of gravity? a
They have small masses and small diameters
b
They have large masses and small diameters
c
They have large masses and large diameters
d
They have small masses and large diameters

A black hole is a region of spacetime where gravity is so strong that nothing no particles or even electromagnetic radiation such as light can escape from it.  Black holes are caused because of a supernova. A supernova is an exploding star that blasts part of the star into space.

The gravity is so strong because matter has been squeezed into a tiny space. That means, the large mass centers into the small diameter so Large mass comes in the small diameter which makes the strong gravity.

(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