For 20 seconds, the speed of the body decreased from 72 km / h to 36 km / h. What is the acceleration of this body?

To find out the acceleration of the specified body, consider the formula: ax = (V – V0) / t, where V is the reduced speed (V = 36 km / h, which in the SI system is 10 m / s); V0 is the initial speed of the conventional body (V0 = 72 km / h, which in the SI system is 20 m / s); t is the duration of the speed reduction (t = 20 s).

Let’s perform the calculation: ax = (V – V0) / t = (10 – 20) / 20 = -0.5 m / s2.

Answer: The acceleration of the indicated body should have been -0.5 m / s2.