An alpha particle (a helium nucleus, containing 2 protons and 2 neutrons) starts out with kinetic energy of 9.6 mev (9.6 × 106 ev), and heads in the direction straight toward a gold nucleus (containing 79 protons and 118 neutrons). the particles are initially far apart, and the gold nucleus is initially at rest. answer the following questions about the collision. what is the initial momentum of the alpha particle? (you may assume its speed is small compared to the speed of light).

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative