- #1

- 45

- 0

## Homework Statement

The motion of a particle is described by x = 10 sin (piet +pie/2 ). At what time ( in second ) is the potential energy equal to the kinetic energy ?

## Homework Equations

KE = 1/2 mv^2 PE=1/2 Kx^2

## The Attempt at a Solution

V=pie10cos(piet + pie/3)

V^2 = pie^2 100cos^2(piet+ pie/3)

KE = mpie5ocos^2 (piet + pie/3)

X^2 =100sin^2(piet +pie/2 )

PE =k50 sin^2(piet +pie/2 )

KE=PE

pie^2 100cos^2(piet+ pie/3) =K50 sin^2(piet +pie/2 )

m/k * pie^2 = tan^2(piet +pie/2 )

take square root of both sides of equation

1/pie * pie = tan(piet + pie/3)

piet + pie/3 =tan-1(1)

solving for t i get a negative value where iam i going wrong.