A physics student on Planet Exidor throws a ball, and it follows the parabolic trajectory shown in figure. The ball's position is shown at 1 s intervals until t =3s. At t=1 s , the ball's velocity is `vec(v)=(2.0 hati+2.0 hatj) m//s`. At 2 sec ball is at its highest point

Options

A. The acceleration of ball is `2 m//s^(2)`
B. speed of ball at highest point is 3 m/s
C. Speed of ball at t=3 sec is `2sqrt(2)` m/s
D. The acceleration of ball is `9.8 m//s^(2)`

Answer

AC

Explanation

For motion (verticle) from t =1 to t=2sec.
`vy=u_(y)+a_(y)t `
`0=2+a_(y)xx1rArr a_(y)=-2 m//sec^(2)`
Speed at highest point =2m/sec
speed at t=3= speed at
`t=1 =sqrt(2^(2)+2^(2)) =2sqrt(2) m//sec`