A lorry with mass of 201 has a tractive resistance of 280N/t at a speed of 72km/h . Calculate power required for that speed
The tractive resistance is given as 280N/t, meaning that for every ton of mass, the lorry will experience a tractive resistance of 280N.
The mass of the lorry is given as 201 tons.
The tractive resistance for the given mass can be calculated by multiplying the tractive resistance per ton by the mass:
Tractive resistance = 280N/t * 201t = 56280N
The speed of the lorry is given as 72 km/h.
To calculate power, we can use the formula:
Power = Force * Velocity
Converting the speed from km/h to m/s:
72 km/h = 72 * (1000 m / 3600 s) = 20 m/s
Plugging in the values:
Power = 56280N * 20 m/s = 1,125,600 N*m/s = 1,125,600 Watts
Therefore, the power required for a speed of 72 km/h is 1,125,600 Watts.