Question

Тело массой 700 кг, под действием силы 3,5 кН трогается с места и разгоняется в течении 3 секунд. Какую скорость приобретет тело и какой путь пройдёт за это время

Answer 1

По второму закону Ньютона F = ma, тогда ускорение, сообщаемое телу приложенной силой, составит: a = F/m = 3500/700 = 5 м/с².
Начальная скорость тела v0 равна нулю. Тогда s = v0·t + at²/2 = 5 · 3²/2 = 45/2 = 22.5 м. 

Answer 2

Given Information:

- Mass of the body: 700 kg - Force acting on the body: 3.5 kN - Time taken to accelerate: 3 seconds

Calculating Velocity:

To calculate the velocity acquired by the body, we can use Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration.

Acceleration can be calculated using the formula: acceleration = force / mass.

Given that the force acting on the body is 3.5 kN (kilonewtons) and the mass of the body is 700 kg, we can calculate the acceleration:

acceleration = 3.5 kN / 700 kg = 5 m/s^2.

Now, we can use the formula for uniformly accelerated motion to calculate the final velocity:

final velocity = initial velocity + (acceleration * time).

Since the body starts from rest (initial velocity = 0), the formula simplifies to:

final velocity = acceleration * time.

Substituting the values, we get:

final velocity = 5 m/s^2 * 3 s = 15 m/s.

Therefore, the body will acquire a velocity of 15 m/s.

Calculating Distance:

To calculate the distance traveled by the body, we can use the formula for uniformly accelerated motion:

distance = (initial velocity * time) + (0.5 * acceleration * time^2).

Since the body starts from rest (initial velocity = 0), the formula simplifies to:

distance = 0.5 * acceleration * time^2.

Substituting the values, we get:

distance = 0.5 * 5 m/s^2 * (3 s)^2 = 22.5 m.

Therefore, the body will travel a distance of 22.5 meters.

Summary:

- The body will acquire a velocity of 15 m/s. - The body will travel a distance of 22.5 meters.

Please note that these calculations assume that the force acting on the body remains constant throughout the acceleration period and that there are no other external factors affecting the motion of the body.