In order for work to be done a force must be exerted on an object causing it to move
The correct answer would be A.The acceleration of gravity is <span>9.81 m/s^2. This is calculated by using the equation:
a = GM/r</span>²
where G is the gravitational constant 6.6726 x 10-11N-m2/kg2, M is the mass of the planet (<span>5.9736E+24 kg) and r is the radius of the planet.
</span>
Matter is defined as anything that has mass and occupies space, it may be classified into three states, solid, liquids or gases. Molecules is the smallest particle of an element that has the chemical properties of the element or the compound. it contains two or more atoms that are joined together. A pure substance is a matter that has distinct properties and a composition that does not vary from sample to sample. Thus the correct answer is C
