Question

Допустим, что вы катитесь на велосипеде по инерции со скоростью 5 м/с. Ваша масса вместе с велосипедом равна 70 кг. Вы наклоняетесь и подхватываете лежащий на земле рюкзак массой 15 кг. Какой станет ваша скорость?

Answer 1

ν1*m1 + ν2*m2 = ν (m1+m2), где m1 - масса с велосипедом, m1  - масса рюкзака, ν1 - ваша скорость, ν2=0 - это скорость рюкзака, ν - скорость после взаимодействия, получаем
5*70 = ν* (70+15)
ν = 4,1 м/с

Answer 2

Calculation of Final Velocity

To calculate the final velocity after picking up the backpack, we can use the principle of conservation of momentum. The initial momentum of the system (you and the bicycle) is equal to the final momentum of the system after picking up the backpack.

The momentum of an object is given by the product of its mass and velocity. Therefore, the initial momentum of the system is:

Initial momentum = (mass of you + mass of bicycle) × initial velocity

The final momentum of the system is:

Final momentum = (mass of you + mass of bicycle + mass of backpack) × final velocity

According to the principle of conservation of momentum, the initial momentum is equal to the final momentum. Therefore, we can set up the following equation:

(mass of you + mass of bicycle) × initial velocity = (mass of you + mass of bicycle + mass of backpack) × final velocity

Now, let's substitute the given values into the equation and solve for the final velocity.

Given: - Mass of you + mass of bicycle = 70 kg - Initial velocity = 5 m/s - Mass of backpack = 15 kg

Substituting these values into the equation:

(70 kg) × (5 m/s) = (70 kg + 15 kg) × final velocity

Simplifying the equation:

350 kg·m/s = 85 kg × final velocity

Dividing both sides of the equation by 85 kg:

final velocity = 350 kg·m/s / 85 kg

Calculating the final velocity:

final velocity ≈ 4.12 m/s

Therefore, your final velocity after picking up the backpack will be approximately 4.12 m/s.