|acceleration| = (change in speed) / (time for the change)
Change in the car's speed = (27 - 0) = 27 m/s
Time for the change = 10 sec
|acceleration| = (27 m/s) / (10 s) = 2.7 m/s² .
That's the magnitude of the car's acceleration.
We don't know anything about its direction.
Initially, the velocity vector is
. At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by
, so the velocity is
.
Converting back to direction and magnitude, we get 
Answer:
the weight of alien is 200 newtons
Explanation:
The computation of the alien weight is shown below:
Given that
Acceleration = 20m/sec^2
And, the mass is 10 kg
So, the weight of alien is
= 20 × 10
= 200 newtons
hence, the weight of alien is 200 newtons
Use Force=Mass x Acceleration (newtons second law states force is directly proportional to the acceleration) so you can say that the force is negative and solve for Acceleration.