Asteroid toutatis passed near earth in 2006 at four times the distance to our moon. this was the closest approach we will have until 2060. if it has mass of 5.0×1013kg , what force did it exert on earth at its closest approach?

The answer is 8.44*10^9 Newton

Explanation:

The equation for universal gravitation is:

Where:

G= 6.674×10^−11 N · (m/kg)^2

M(earth)=5.972 × 10^24 kg

M(asteroid)=5.0×10^13 kg

r=1.537*10^9 m (Calculated from average distance between moon and earth)

The force will be:

8.44*10^9 Newton

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c is 100% but i am confused in a