Suppose an experiment measures a mass, heats it over a flame without changing its state, measures it again, and finds the mass to be different. which statement best describes the kind of change that could have taken place a. physical change because the substance became more denseb. chemical change because mass was lost, most likely as a gasc. chemical change because the chemical property of mass changedd. physical change because the mass melted going from a solid to a liquid

B. Chemical change because mass was lost

Explanation:

When experiment was done then at the end, the state of the specimen did not changed but the mass varied this certainly means it is a chemical change.

A chemical change can be describes as a change after which the properties of the reactant get changed and can never be replenished again.

It is termed as irreversible reaction as the original reactant cannot be taken out of the final product.

Mass of the reactant is not equal to the mass of the product and state is still the same which means there must be some chemical reaction that have taken place which is responsible for this loss of mass.

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