Solve Rock Problem Part 2: Time to Push 50Kg Rock 10m

[29 clicks]

This is the second hardest question on my test, how long does it take to push a rock 10m.

50Kg rock
10 m is the distance
0.16m/s2 is the acceleration

Does anyone know which kinematics equation I should use for this problem.

 

[matrixx333]

The four kinematic equations are:

d = v_i*t + 1/2*a*t²

v_f = v_i + a*t

v_f² = v_i² + 2*a*d

d = v_i + v_f/2 *t

You want to pick the equation that has a "t" in it, and the one that has the most of your information already provided.

P.S. your initial velocity is 0 m/s, remember!

 

[29 clicks]

I know its the first equation since i have all the information except for t, but I'm not good at rearranging question so can you help me just a bit more. Really appreciate it.

 

[matrixx333]

ok, so let's substitute the values for what we "know"

d = v_i*t + 1/2*a*t², which would equal:

10 = (0)*t + 1/2*(.16)*t²

we want to try and solve for t, in the first part of the equation, (0)*t, we know that equals 0, so we can get rid of that part, now our equation is:

10 = 1/2*(.16)*t²

can you take it from there?