A car weighing m = 2.8 tons starts. After a time interval t = 2 s from the beginning of the movement

| June 11, 2021 | education

A car weighing m = 2.8 tons starts. After a time interval t = 2 s from the beginning of the movement, the power of the engine thrust is P = 35 kW. ignoring the resistance forces, determine the vehicle’s acceleration module.

To find out the acceleration modulus of the specified vehicle, consider the formula: P = A / t = ΔEk / t = ma * V ^ 2 / 2t = ma * (a * t) 2 / 2t = ma * a ^ 2 * t / 2, whence we express: a = √ (2P / (ma * t)).

Data: P – traction force of the engine of the specified vehicle (P = 35 kW = 35 * 10 ^ 3 W); mа is the mass of the car (mа = 2.8 t, in the SI system mа = 2.8 * 10 ^ 3); t – time interval (t = 2 s).

Let’s perform the calculation: a = √ (2P / (ma * t)) = √ (2 * 35 * 10 ^ 3 / (2.8 * 10 ^ 3 * 2)) = √12.5 ≈ 3.536 m / s2.

Answer: The required acceleration module of the specified vehicle should be 3.536 m / s2.



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