Ahelicopter’s speed increases from 25 m/sec to 60 m/sec in 5 seconds. what is the acceleration of this
helicopter?

7 m/s^2

Explanation:

Acceleration = Vf - Vi / t, where Vf is the final velocity, Vi is the initial velocity, and t is the time. It is given that the helicopter’s speed increases from 25 m/s to 60 m/s in 5 s, so Vf = 60 m/s, Vi = 25 m/s, and t = 5. When putting this into the equation you get 60 - 25 / 5 which can simplify to 35 /5 also known as 7 m/s^2.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

its a circle not a square that's simple silly.

explanation: