Activity A: Problems on Spherical Mirror . A 5cmhigh object is placed in front of a concave mirror with a radius of curvature of 20 cm. Determine the image height if the object distance is 5 cm, 15 cm. . An image by a concave mirror is 4 times greater than the object. If the radius of curvature is 20 cm, determine the object distance in front of the mirror. . A 1-cm high object is placed 10 cm from a concave mirror with the focal length, f= 15 cm. Determine : a. The image distance ? b .The image height? c. The properties of the image formed by the concave mirror? ACTIVITY B: PROBLEM SET Directions: Solve the following problems. Show your complete solutions. Express the nal answers in two decimal places. 1. A spacecraft is moving relative to the earth. An observer on the earth finds that, between 3 PM and 4 PM according to his clock, 3601 s elapsed on the spacecraft's clock. Calculate the spacecraft's speed relative to the earth. 2. An observer sees a spacecraft, measured as 100 m long when at rest, pass by in uniform motion with a speed of 0.500s. Find the length of the moving spacecraft as measured by the observer. 3. If a spaceship is approaching the Earth at 0.100c and a message capsule is sent toward it at 0.1000 relative to the Earth, what is the speed of the capsule relative to the ship? 4. Calculate the relativistic momentum of a helium nucleus having a mass of 6.68 x 1027 kg that is moving at 0.200c. 5. The total energy of a particle is 4.45 times its rest energy. The mass of the particle is 3.5 x 10-27 kg. (a) Find the particle's rest energy. (b) With what speed is the particle moving? (c) Determine the kinetic energy (MeV) of the particle. (1 J = 6.24ZX1012 MeV)