An astronomer discovers a massive galaxy which has four nuclei. What is a likely explanation for a galaxy having more than one nucleus

Aclarinetist, setting out for a performance, grabs his 3.350 kg clarinet case (including the clarinet) from the top of the piano and carries it through the air with an upward force of 24.65 n. find the case's vertical acceleration. indicate an upward acceleration as positive and a downward one as negative.

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?

What is the coefficient of kinetic friction μk between the block and the tabletop?