Which statement is true about black dwarfs?
a. none currently exist in the universe.
b. they are very hot and massive.
c. they burn brightly for only a few weeks or months.
d. they form after supernova explosions.

Determine the maximum r-value of the polar equation r =3+3 cos 0

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.

Question 1 of 15 2 points when doing science as inquiry, you should have some idea of what you think the final result will be. o a. true o b. false submit