How many neutrons does element X have if it's atomic number is 21 and it's mass number is 75

In a downhill ski race, surprisingly, little advantage is gained by getting a running start. (This is because the initial kinetic energy is small compared with the gain in gravitational potential energy even on small hills.

Two technicians are discussing a floating-type disc brake caliper. Technician A says that if the caliper slides are corroded, one pad may wear more than the other pad on the same wheel brake.

Jess rides her motorcycle at an average speed of 20 m/s for 500 seconds. how far did she ride

A car travels at 20 meters per second. What is its rate in kilometers per hour? 72 kilometers per hour 5.6 kilometers per hour 1.2 kilometers per hour 56 kilometers per hour

How much heat is absorbed by a 29g iron skillet when its temperature rises from 9oC to 105oC?

An object has a mass of 8.00 kg. What is the gravitational force on the object by the earth?

Which of the following best characterizes the free energy change ΔG for an endothermic reaction under physiological conditions? A. The sign of ΔG is positive B. The sign of ΔG is zero C. The sign of ΔG is negative D.

In a recent hockey game, one player (m=100kg) was moving at a velocity of 8 m/s when he ran into another player (m=300kg) who was at rest (v=0m/s). After the collision, the two players were stuck together (moving with the same velocity).

In a laser, electrical energy is changed to light energy, and a small amount of the energy is wasted as heat. Describe the total amount of the heat in the system (using the conservation of energy).

What is the name for a star and planets held together by gravity? A. solar system B. galaxy C. black hole D. supernova