Darin skateboarded to the north at 4 m/s. in 5 seconds, he sped up to 7 m/s. what was his acceleration? a. -0.6 m/s2 north b. -1.66 m/s2 north c. 0.6 m/s2 north d. 1.66 m/s2 north

To solve this problem we can use following equation.

v =u + at

Where v is the final velocity (m/s), u is the initial velocity (m/s), a is the acceleration (m/s²) and t is the time taken (s).

v = 7 m/s
u = 4 m/s
a = ?
t = 5 s

By applying the equation, we can get
    7 m/s = 4 m/s + a x 5 s
    3 m/s = a x 5 s
          a = 0.6 m/s²

Hence, the acceleration is 0.6 m/s² towards north.

Answer is "C".

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.