Question

a person lift a box of weight 70kg from the height of 2meter calculate the work done by the person on the box​

Answer 1

Answer:

Magnesium ribbon burns with dazzling white light, once treated to its ignition temperature. The white powder formed is Magnesium oxide which dissolves in water to give a basic solution which turns red litmus blue. Thus 'x' is Mg and 'y' is MgO.

Answer 2

Given :

Mass of the box = 70kg

Height = 2m

To Find :

Work done by the person on the box.

Solution :

❒ Work done is defined as the product of force and displacement.

Mathematically, W = F • d

• W denotes work done
• F denotes force
• d denotes displacement

Work is a scalar quantity having only magnitude.

♦ SI unit : J

♦ CGS unit : erg

♦ Remember : 1 J = 10⁷ erg

Here force acting on the box is weight force which is equal to mg$.$

➙ W = F • d

➙ W = mg • d

By substituting the given values;

➙ W = (70 × 10) • 2

➙ W = 700 × 2

➙ W = 1400 J