Question

define 1 joule of work .calculate the work done in lifting up box weight 150 kg through a vertical height of 7 m.

Answer 1

⭐1 Joule of work is said to be done when a force of 1 newton displaces a body through a distance of 1 metre in its own direction.
⭐ work done= force × displacement
given mass= 150 kg and displacement= 7m
force=mg.
force= 150×9.8 = 1470 N
now, from above formula
w= f× s
= 1470 × 7 = 10290 J. ans....

Answer 2

Definition of 1 Joule :

• 1 Joule is the work done to move a body with a force of 1 Newton by 1 metre displacement.

Given:

• Mass of box = 150 Kg
• Vertical height attained = 7 metres

To find:

• Work done ?

Calculation:

The work done to lift the box to that height will be equal to the GRAVITATIONAL POTENTIAL ENERGY attained by the box.

$\therefore \: work = PE$

$\implies \: work = m \times g \times h$

$\implies \: work = 150 \times 10 \times 7$

$\implies \: work = 10500 \: joule$

$\implies \: work = 10.5 \:kilo joule$

So, work done to attain the height is 10.5 kJ.