Solving for Time Change: a=-300v^2

[lycheeliang]

Homework Statement

From eqn a=-300v^2
Find time taken for acceleration to change from 1.50ms^-1 to 0.75ms^1

Homework Equations

a=dv/dt

The Attempt at a Solution

I tried integrating, but still cannot get the ans.

 

[JohnDuck]

This is a simple differential equation. Try separation of variables.

 

[Dick]

JohnDuck is quite right, except I think the usual term is 'separable' rather than 'separation of variables'. And it is fairly easy. You'll just have to be clearer to us where you are confused.

 

[HallsofIvy]

"separable' is the adjective, "separation" the noun. Yes, this is a "separable" equation and the technique for solving is "separation of variables"- you are both right.

lycheeliang, you have dv/dt= -300v² so, separating the variables (the verb form!) you have dv/v^2 = -300dt. Integrate both sides of that.

 

[lycheeliang]

oh thanks!