An airplane starts from rest and accelerate at a constant 3.00m/s^2 for 20.0 seconds what is its displacement in this time ?

It says acceleration is constant so velocity becomes zero.

Explanation:

S = 1/2* a * t^2

S = 1/2* 3 * 20^2

S=1/2*3*400

S=1/2*1200

S=600m

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )