A helium atom (m = 6.646 × 10−27) collides elastically with an oxygen atom (m = 2.656 × 10−26) at rest. After the collision, the helium atom is found to be moving with a velocity of 6.636×106 m/s in a direction at an angle of 84.7◦ relative to its original direction. The oxygen atom is observed to move at an angle of -40.4◦.

(a) Find the velocity of the oxygen atom after the collision.
(b) Find the speed of the helium atom before the collision.

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

The force will determine the acceleration.

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.