An article states that the fission of 2.0 g of uranium−235 releases 6.8 × 108 kcal, the same amount of energy as burning two tons (4,000 lb) of coal. if this report is accurate, how much energy is released when 1.0 g of coal is burned?

340 kcal

Explanation:

Energy released by 2 g of Uranium is same as the energy released by 2 tons of coal.

Energy given by 2 tons of coal = 6.8 x 10^8 kcal

Energy given by 2 x 10^6 g of coal = 6.8 x 10^8 kcal

Energy released by 1 g of coal = (6.8 x 10^8) / (2 x 10^6) = 340 kcal

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards