Aforce is applied to a block sliding along a surface (figure 2). the magnitude of the force is 15 n , and the horizontal component of the force is 4.5 n . at what angle (in degrees) above the horizontal is the force directed?

Thus, the force is directed 72.5° above the horizontal.

Explanation:

The magnitude of the force, F = 15 N

let this force be detected at angle θ from the horizontal, then horizontal component of force is: F cos θ

and vertical component is F sin θ

Horizontal component is given,

F cos θ = 4.5 N

⇒15 N cos θ = 4.5 N

⇒ cos θ = 0.3

⇒ θ = cos⁻¹ 0.3 = 72.5°

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.