Question

Из неподвижной лодки, масса которой 80 кг, прыгает на берег мальчик. масса мальчика 40 кг, скорость его при прыжке 2м/с. какую скорость приобрела лодка? Но мы не проходили импульсы

Answer 1

P1 =v×m
p1 = 80 × 2 =160
V2 = 160/40 = 4

Answer 2

Calculation of the Boat's Velocity

To calculate the velocity acquired by the boat when the boy jumps off it, we can use the principle of conservation of momentum. According to this principle, the total momentum before the jump is equal to the total momentum after the jump.

The momentum of an object is given by the product of its mass and velocity. Therefore, the momentum of the boat before the jump is equal to the momentum of the boy after the jump.

Let's denote the mass of the boat as m1 (80 kg) and the mass of the boy as m2 (40 kg). The velocity of the boy before the jump is v2 (2 m/s). We need to find the velocity of the boat after the jump, which we'll denote as v1.

According to the conservation of momentum, we have:

m1 * v1 = m2 * v2

Substituting the given values:

80 kg * v1 = 40 kg * 2 m/s

Simplifying the equation:

v1 = (40 kg * 2 m/s) / 80 kg

Calculating the result:

v1 = 1 m/s

Therefore, the boat acquires a velocity of 1 m/s when the boy jumps off it.

Please note that this calculation assumes an idealized scenario where there are no external forces acting on the system (such as friction or air resistance).