Many scientists believe that the dinosaurs were killed in a large-scale extinction event.
if a large meteor of mass 6.2 × 1010 kg and speed of 2.2 × 104
struck earth at that time, it
would alter the rotational velocity of the planet.
assuming the rotational speed after the meteor struck was (and still is) 1 rev/23.93 hours1
,
how long was a day before the meteor struck?

Athin, square metal plate measures 14 cm on each side and has emissivity of 0.60. the plate is heated to a temperature of 745°c. what is the rate at which the plate radiates energy ? the stefan-boltzmann constant is 5.67 × 10-8 w/(m2 ? k4). remember that the plate will radiate energy from both its top and bottom surfaces.

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics