A cannon of a pirate ship of the eighteenth century had a mass of 2000 pounds and fired 10-pound projectiles at a speed of 300 m/s. The cannon is in the horizontal position, and the speed of the projectile is constant inside. Determine the speed recoil of the cannon. Assume 1 pound equal to 450 grams.

Solution

In the figure, m_A = 1 kg and m_B = 2 kg, the plane is frictionless, and the spring has a negligible mass. Initially, the spring is compressed between the blocks then the system is released at rest. The blocks are pushed apart, and the spring falls for not being attached to any of them. Body B acquires a speed of 0.5 m/s. Determine the elastic potential energy of the spring at the moment the system is released.

Solution

A body with a mass of 2 kg, and a speed of 4 m/s in the horizontal direction, receives the impulse of a force. Its speed change to 3 m/s to the vertical direction. Knowing that the force acted in the particle in a time interval that lasted 1 ms, determine:
a) The impulse received by the particle;
b) The force that acts in the particle.

Solution

From the top of a 100 m tall building is relesead at rest, a 900 g mass brick under the action of gravitational force. Find:
a) The speed of the brick when touching the floor;
b) The momentum of brick by touching the floor;
c) The impulse of force acting on brick during fall.

Solution 1

Solution 2

Two bodies, A and B, identical and of the same mass, are on a horizontal surface. Initially, body A has a speed v₀ = 5 m/s, and body B is at rest. Body A collides with body B in a head-on elastic collision. Show that, in these conditions, after the collision, the speeds of bodies will be exchanged.

Solution