When braking in front of a traffic light, the car moved uniformly and in a straight line with an acceleration of 4 m

| September 16, 2021 | education

When braking in front of a traffic light, the car moved uniformly and in a straight line with an acceleration of 4 m / cm2. With what speed did the car move 10 s after the moment of the beginning of braking, if the speed of the car at the moment of the beginning of braking was equal to 72 km / h?

a = 4 cm / s2 = 0.04 m / s2.

V0 = 72 km / h = 20 m / s.

t = 10 s.

V -?

The acceleration of a car shows how its speed changes over time. The acceleration of the car a during braking is expressed by the formula: a = (V0 – V) / t, where V0 is the initial speed during braking, V is the final speed, t is the braking time.

V0 – V = a * t.

The final speed of the car during braking is found by the formula: V = V0 – a * t.

V = 20 m / s – 0.04 m / s2 * 10 s = 19.6 m / s.

Answer: the vehicle speed will become V = 19.6 m / s.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.