# With the help of a rope, the load begins to be lifted vertically upwards with uniform acceleration.

With the help of a rope, the load begins to be lifted vertically upwards with uniform acceleration. The rope acts on the load with a force of 63.3N. In 3 seconds, the load was lifted to a height of 12m. What is the weight of the cargo?

N = 63.3 N.

t = 3 s.

h = 12 m.

g = 9.8 m / s2.

V0 = 0 m / s.

m -?

When the load is lifted up, 2 forces act on it: gravity Ft directed vertically downward, and rope tension force N directed vertically upward.

m * a = F + N – 2 Newton’s law in vector form.

We will direct the coordinate axis of the OU vertically upward.

For projections on the OU 2 axis, Newton’s law will take the form: m * a = – Ft + N.

N = m * a + Fт.

The force of gravity Ft is determined by the formula: Ft = m * g.

N = m * a + m * g = m * (a + g).

m = N / (a ​​+ g).

Since the load begins to move from a state of rest V0 = 0 m / s, then h = a * t ^ 2/2.

a = 2 * h / t ^ 2.

a = 2 * 12 m / (3 s) ^ 2 = 2.7 m / s2.

m = 63.3 N / (2.7 m / s2 + 9.8 m / s2) = 5 kg.

Answer: the mass of the cargo is m = 5 kg. 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.