Question

:) A point mass starts moving in a straight line with constant acceleration "a" At a timet
after the begining of motion, the acceleration changes sign, with out change in magnitude
Determine the time to from the beginning of the motion in which the point mass returns to
the initial position​

Answer 1

Answer:

let s be the distance travled in time t

s=

2

at

2

…(1)

let t

1

be the time in which it comes to its initial position

using equation of motions=ut+

2

at

2

now u=at,t=t

1

,s=−s,a=−a

−s=(at)t

1

−

2

at

1

2

s=−att

1

+

2

at

1

2

…(2)

using (1)&(2)

t

1

2

−2tt

1

−t

2

solving t

1

=(

2

+1)t

t

0

=t

1

+t

t

0

=(

2

+2)t