Question

Тело массой 2 кг упало с высоту 4,9 м. Найдите импульс тела в конце падения?

Answer 1

Энергия E=mgh=mV²/2; V²=2gh; V= √(2gh); 
импульс тела P=mV=m*√(2gh) = 2·√(2·10·4.9)=19.8 кг·м/с; 

Answer 2

Calculation of Impulse

To find the impulse of an object at the end of its fall, we need to use the formula:

Impulse = Change in momentum

The momentum of an object is given by the product of its mass and velocity. In this case, we are given the mass of the object (2 kg) and the height from which it falls (4.9 m). To find the velocity at the end of the fall, we can use the equation for gravitational potential energy:

mgh = (1/2)mv^2

Where: - m is the mass of the object (2 kg) - g is the acceleration due to gravity (9.8 m/s^2) - h is the height from which the object falls (4.9 m) - v is the velocity of the object at the end of the fall

We can rearrange this equation to solve for v:

v = sqrt(2gh)

Now, we can calculate the velocity at the end of the fall:

v = sqrt(2 * 9.8 * 4.9) = 9.8 m/s

Next, we can calculate the initial momentum of the object:

Initial momentum = mass * initial velocity

Since the object is initially at rest, the initial velocity is 0. Therefore, the initial momentum is 0.

Finally, we can calculate the impulse of the object at the end of the fall:

Impulse = Change in momentum = Final momentum - Initial momentum

Since the initial momentum is 0, the impulse is equal to the final momentum:

Impulse = Final momentum = mass * final velocity

Substituting the values:

Impulse = 2 kg * 9.8 m/s = 19.6 kg·m/s

Therefore, the impulse of the object at the end of the fall is 19.6 kg·m/s.