Why is the H-R diagram useful in plotting the life cycles of stars?

A closed, rigid tank contains a two-phase liquid-vapor mixture of Refrigerant 22 initially at - 20°C with a quality of 50.36%. Energy transfer by heat into the tank occurs until the refrigerant is at a final pressure of 6 bar.

Which statements best describe X-rays?

Work of 5 Joules is done in stretching a spring from its natural length to 19 cm beyond its natural length. What is the force (in Newtons) that holds the spring stretched at the same distance (19 cm) ? Don't forget to enter the correct units.

Which gas law describes the relationship between temperature and pressure at a constant volume

Consider the markets for BP supreme-grade gasoline, all BP grades of gasoline, and all gasoline. For which of these three markets will demand be most elastic? Demand will be most elastic for?

A battleship simultaneously fires two shells toward two identical enemy ships. One shell hits ship A, which is close by, and the other hits ship B, which is farther away. The two shells are fired at the same speed.

A horse canters away from its trainer in a straight line, moving 37 m away in 9.1 s. It then turns abruptly and gallops halfway back in 1.8 s. Calculate its average speed for the entire trip. Express your answer using two significant figures.

An early submersible craft for deep-sea exploration was raised and lowered by a cable from a ship. When the craft was stationary, the tension in the cable was 7000 N {/rm N}.

What are the components of earths life support system

A car is moving with a velocity (3.0 m/s) € x ˆ + (1.0 m/s) € y ˆ and 3.0 seconds later its velocity is (6.0 m/s) € x ˆ - (3.0 m/s) € y ˆ. What is the direction of the average acceleration of the car?