Question

Seth is accelerating at a rate of -2.8 m/s2. How long would it take him to go from 87 m/s to 12 m/s?

Answer 1

Answer:

The answer will be 750/28 second or 26.78 second;

Explanation:

Acceleration = -2.8 m/s2;       {here, acceleration can also be replaced with retardation since, the value of acceleration is negative integer. But the value of retardation will be given as 2.8 m/s2 (no negative sign)}

Initial velocity (u)= 87 m/s;

Final Velocity (v)= 12 m/s;

Relation of time, initial velocity, final velocity and acceleration is given as;

                         v = u + at;                          (i)

where, v = final velocity;

            u = initial velocity;

            a = acceleration;

and,       t = time;

Thus, using eq.(i) and given things, we can deduce that;

                      12 = 87 + (-2.8)t;

                     2.8t = 87 - 12;

                       2.8t = 75;

                          t = 75/2.8 = 26.78 sec;

That's all.