A trolleybus weighing 12 tons starts to move with an acceleration of 1.5 m / s2.

| March 11, 2021 | education

A trolleybus weighing 12 tons starts to move with an acceleration of 1.5 m / s2. On the first 20 m of the journey, the trolleybus acquires kinetic energy equal to …

m = 12 t = 12000 kg.

a = 1.5 m / s ^ 2.

V0 = 0 m / s.

S = 20 m.

Ek -?

The kinetic energy of the body Ek is determined by the formula: Ek = m * V ^ 2/2, where m is the mass of the trolleybus, V is the speed of the trolleybus.

For movement with constant acceleration, the following formula is valid: S = (V ^ 2 – V0 ^ 2) / 2 * a.

Since V0 = 0, the formula will take the form: S = V ^ 2/2 * a.

The formula for determining the speed of a trolleybus will be: V ^ 2 = 2 * a * S.

Ek = m * 2 * a * S / 2.

Ek = 12000 kg * 2 * 1.5 m / s ^ 2 * 20 m / 2 = 360,000 J = 360 kJ.

Answer: the trolleybus has a kinetic energy Ek = 360 kJ.



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.