Aperson of mass 80 kg stands on earth's surface. what is his weight?

89 n

480 n

784 n

980 n

784N

Explanation:

Yo need to multiply the mass of the person by th Earth's gravity, which we know is 9.8m/s²

80kg*9.8m/s² = 784N

The weight of the person on the Earth's surface is 784N

Solution:

The weight and mass are separate things. The weight of the person includes the gravitational acceleration along with the mass of the person as per Newton’s second law.  

So,

Here the mass = 80 kg

We know the gravitational acceleration =

So the weight of the person =

8 years

Explanation:

Kepler's third law states that the ratio between the cube of the distance of a planet from its star and the square of its orbital period is constant for all the planets orbiting around that star:

where d is the distance of the planet from the star and T is the orbital period.

By applying this law to the two planets of this problem, we can write

where is the distance of geos from the star, is its orbital period, is the distance of logos from the star. Re-arranging the equation , we can find , the orbital period of logos around the star: