0.15=0.5*9.81*t^2

Solution for 0.15=0.5*9.81*t^2 equation:

Simplifying
0.15 = 0.5 * 9.81t2

Multiply 0.5 * 9.81
0.15 = 4.905t2

Solving
0.15 = 4.905t2

Solving for variable 't'.

Move all terms containing t to the left, all other terms to the right.

Add '-4.905t2' to each side of the equation.
0.15 + -4.905t2 = 4.905t2 + -4.905t2

Combine like terms: 4.905t2 + -4.905t2 = 0.000
0.15 + -4.905t2 = 0.000

Add '-0.15' to each side of the equation.
0.15 + -0.15 + -4.905t2 = 0.000 + -0.15

Combine like terms: 0.15 + -0.15 = 0.00
0.00 + -4.905t2 = 0.000 + -0.15
-4.905t2 = 0.000 + -0.15

Combine like terms: 0.000 + -0.15 = -0.15
-4.905t2 = -0.15

Divide each side by '-4.905'.
t2 = 0.03058103976

Simplifying
t2 = 0.03058103976

Take the square root of each side:
t = {-0.174874354, 0.174874354}