Answer:
Work cause a change in kinetic energy
D. <span>Johannes Kepler argued that Earth was the center of the universe.
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Answer:

Explanation:
Given:
Mass of the cannonball (M) = 20 kg
Mass of the marble (m) = 0.002 kg
Distance between the cannonball and marble (d) = 0.30 m
Universal gravitational constant (G) = 
Now, we know that, the gravitational force (F) acting between two bodies of masses (m) and (M) separated by a distance (d) is given as:

Plug in the given values and solve for 'F'. This gives,

The same force is experienced by both cannonball and marble.
Therefore, the gravitational force of the marble is 
Explanation:
Momentum before collision:
(2 kg) (4 m/s) + (5 kg) (-3 m/s) = -3 kg m/s
No external forces act on the balls, so momentum is conserved. Therefore, momentum after collision is also -3 kg m/s.
Any lump of osmium is. Iridium and gold are also very close.