Calculate the magnitude of the normal force on a 25.2 kg block in the following circumstances. (enter your answers in n.) hint (a) the block is resting on a level surface. n (b) the block is resting on a surface tilted up at a 30.8° angle with respect to the horizontal. n (c) the block is resting on the floor of an elevator that is accelerating upward at 2.78 m/s2. n

when the body is resting N = 246.96 N

when the body is resting on a tilted surface N = 212.12 N.

when the body is in a elevator N = 317.036 N

Explanation:

when the block is resting on a stationary surface the normal force is balanced by the weight of the body.

weight of the body = mg = 25.2×9.8 = 246.96 N

therefore normal force = 246.98 N.

when the block is resting on a tilted surface the normal force will be balanced by the component of the weight where Ф is the angle of inclination.

therefore N = mg

                N= 212.12 N.

when the block is resting on a elevator that is accelerated upward the normal force will be the sum of weight and force due to acceleration ma

therefore N = 246.98 + 25.2×2.78

N = 317.036 N

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.