a 40 kg ballet dancer stands on her toes during a performance with four square inches (26cm squared, in contact with the floor and the pressure is 151,000 pa . what is the pressure exerted by the floor over the area of contact if the dancer is leaping upwards with an acceleration of 6.00 m/s squared

According to the law of conservation of mass, in a chemical reaction the total starting mass of all the reactants equal the total final mass of all the products. true or false?

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

An atom that has gained or lost electrons is called an _