PLEASE HELP <3 What is the radius of the event
horizon for Cygnus X-1?
A. 21 m
B. 21 km
C. 21 AU
D. 21 light years

(Assume that Cygnus X-1 has 7 times the mass of the Sun and is not rotating. One solar mass = 1.99 x 10^30 kg)

Which expression allows you to determine the mechanical advantage of an inclined plane? a. height of plane / input force b. length of plane / input force c. length of plane / height of plane d. height of plane / length of plane

What is the magnitude of the resultant vector round your answer to the nearest tenth

Aprojectile is launched from ground level with an initial velocity of v 0 feet per second. neglecting air resistance, its height in feet t seconds after launch is given by s equals negative 16 t squared plus v 0 t. find the time(s) that the projectile will (a) reach a height of 192 ft and (b) return to the ground when v 0equals112 feet per second. (a) find the time(s) that the projectile will reach a height of 192 ft when v 0equals112 feet per second. select the correct choice below and, if necessary, fill in the answer box to complete your choice.