Physics Homework Question?

Question

A child in a boat throws a 5.85-kg package out horizontally with a speed of 10.0 m/s. The mass of the child is 22.8 kg and the mass of the boat is 38.4 kg .

 

Calculate the velocity of the boat immediately after, assuming it was initially at rest.

Express your answer to three significant figures and include the appropriate units. Enter positive value if the direction of the force is in the direction of the velocity of the box and negative value if the direction of the force is in the direction opposite to the velocity of the box.

 

Answer 1

The object mass is .

The object moves with a velocity of .

The mass of the child is .

The mass of the boat is .

Find the velocity of the boat .

The initial momentum of the system is zero because the boat, child, and package all are at rest.

Momentum after the child throws the package horizontally.

Momentum after the child throws the package horizontally .

Conservation of momentum:

The momentum before child throws the package is equal to momentum after the child throws the package.

Negative sign indicates that the boat moves in opposite direction to the package.

The magnitude of velocity of the boat after the child throws the package is m/sec.