Given a right triangle abc, which of the following statements must be true? check all that apply pic in comments

a) sina=cos (90-c)
b)cosa=sinc
c) sina=cos(90-a)
d) angle a and angle c are supplementry

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n