Question

How much would a 70 kg man weigh on the moon? What would be his mass and weight on the earth (Acceleration due to gravity on moon = 1.63 m/s2)

Answer 1

Weight: defined as the force of attraction applied by the planet on the object.

• This attractive force is known as gravitational attraction.

$\implies\rm W_{planet} = mg_{planet}$

Solution:

(1) Weight of man on the moon?

$\to\rm W_{moon} = mg_{moon}$

$\to\rm W_{moon} = 70\times 1.63$

$\to\bf W_{moon} = 114.1 \: N$

(2) Weight of man on the earth?

-- we know that acceleration due to gravity on earth is 9.8 m/s².

$\to\rm W_{earth} = mg_{earth}$

$\to\rm W_{earth} = 70\times 9.8$

$\to\bf W_{moon} = 686 \: N$

(3) mass of object on earth?

-- most important point to note, mass is the measure of matter or particles present in the object.

• for that reason, mass is irrespective of the surrounding planet or suitation(except nuclear reactions)

★ mass will remain same as in the moon or earth or any planet.

$\to\bf m_{moon} = m_{earth} = 70\: kg$

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