Question

A particle starts from a point with a velocity of +6,0
m/s and moves with an acceleration of -20 m/s2
Show that after 6 s the particle will be at the starting
point

Hints answer is 40/3 km
Please explain ​

Answer 1

Answer:

Explanation:

We have the following information:  ∘ Initial velocity of the particle: vi=6m/s  ∘ Time: t=6s  ∘ Acceleration: a=−2m/s2  ∘ Displacement: d=?    Then, the displacement of the particle is given by:  d=vit+

1

2

 

at2  We can say that a particle that starts from a starting point and after a time t reaches   the same starting point has had a displacement equal to zero. Then, when t=6s:  d=(6m/s)(6s)+

1

2

 

(−2m/s2)(6s)2  d=36m−36m=0    Therefore, we can say that the particle reaches the starting point when t=6s, as its  displacement is zero.