What work does a constant force do to move a 5 m body with a mass of 3 kg on a smooth horizontal
What work does a constant force do to move a 5 m body with a mass of 3 kg on a smooth horizontal surface if the body’s acceleration modulus is 2 m / s ^ 2?
S = 5 m.
m = 3 kg.
a = 2 m / s2.
A -?
Mechanical work A is determined by the product of the force F and the displacement of the body S and the cosine of the angle between them ∠α: A = F * S * cosα. We will assume that a force F acts on the body in the direction of its displacement S, therefore ∠α = 0 °, cos0 ° = 1, A = F * S.
According to 2 Newton’s law, when the body acts on a constant in magnitude and direction of the force F, the body moves with a constant acceleration a, the value of which is determined by the formula: a = F / m.
F = m * a.
Mechanical work will be determined by the formula: A = m * a * S.
A = 3 kg * 2 m / s2 * 5 m = 30 J.
Answer: the force performs mechanical work A = 30 J.