Because not all stars are the same distance from earth, it can be difficult to determine?
a. the brightness of a star
b. the position of a star in the night sky
c. whether or not a particular star is real
d. if a star can be seen with a telescope

Asystem containing an ideal gas at a constant pressure of 1.22×10^5 pa gains 2140 j of heat. during the process, the internal energy of the system increases by 2320 j. what is the change in volume of the gas?

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

This punnett square shows the cross between two pants. one parent has round seeds (rr). and the other parent has wrinkled seeds (rr) which best describes their offspring as shown in this cross?