4. A ship flies at 0.82c and is observed by ground-based radar to be 65 m in length. What is the ship's proper length? a) b) c) 96 m 114 m 88 m d) e) 143 m 131 m

A star is 12.2 ly (light-years) from Earth. HINT (a) At what constant speed (in m/s) must a spacecraft travel on its journey to the star so that the Earth–star distance measured by an astronaut onboard the spacecraft is 4.36 ly?  m/s (b) What is the journey's travel time in years as measured by a person on Earth?   NO SCIENTIFIC NOTATION ANSWERS THANK YOU

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 10. How far apart must two objects on the moon be to be resolved by a telescope which has a 7.80-m diameter mirror? The wavelength of the light used is A610 nm, and the distance to the moon to be 3.80 x 105 km. a) 24.4 m b) 29.7 m c) 36.3 m d) 72.5 m e) 12.2 m 11. A converging lens with a focal length of (f₁ = 32.0 cm) is placed 42.0 cm to the left of a diverging lens with a focal length of (f2 = -25.5 cm). An object is placed 40.0 cm to the left of the converging lens. What is the location of the image produced by the combination of lenses? a) 32.5 cm to the right of the diverging lens b) 32.5 cm to the left of the diverging lens c) 160 cm to the left of the…

2. A ladder 5.50 m long leans against a wall inside a spaceship. From the point of view of a person on the ship, the top of the ladder is 4.61 m above the floor. The spaceship moves past the Earth with a speed of 0.80c in a direction parallel to the floor of the ship. What is the length of the ladder as seen by an observer on Earth?