9. An astronomer on earth observes two spacecraft moving away from each other along an axisthat passes through the earth. The astronomer measures the speed of each spacecraft to be0.875c relative to the earth. At what speed are the spacecrafts moving apart relative to eachother?a) 0.496cb) 0.467cc) 1.750cd) 0.143ce) 0.991c10. How far apart must two objects on the moon be to be resolved by a telescope which has a7.80-m diameter mirror? The wavelength of the light used is A610 nm, and the distanceto the moon to be 3.80 x 105 km.a) 24.4 mb) 29.7 mc)36.3 md) 72.5 me) 12.2 m11. A converging lens with a focal length of (f₁ = 32.0 cm) is placed 42.0 cm to the left of adiverging lens with a focal length of (f2 = -25.5 cm). An object is placed 40.0 cm to the leftof the converging lens. What is the location of the image produced by the combination oflenses?a) 32.5 cm to the right of the diverginglensb) 32.5 cm to the left of the diverging lensc) 160 cm to the left of the diverging lensd) 160 cm to the right of the diverginglense) 118 cm to the left of the diverging lens↑I4

Speed of each spacecraft Relative speed

9. An astronomer on earth observes two spacecraft moving away from each other along an axis that passes through the earth. The astronomer measures the speed of each spacecraft to be 0.875c relative to the earth. At what speed are the spacecrafts moving apart relative to each other? a) 0.496c b) 0.467c c) 1.750c d) 0.143c e) 0.991c

9. An astronomer on earth observes two spacecraft moving away from each other along an axis that passes through the earth. The astronomer measures the speed of each spacecraft to be 0.875c relative to the earth. At what speed are the spacecrafts moving apart relative to each other? a) 0.496c b) 0.467c c) 1.750c d) 0.143c e) 0.991c