(1) Evaluate (5i + 3j + 7k) - (i 3j). Round the nearest tenth. (2) Find the value 15 for which (9 t, 17 +75, 6 + 315) is orthogonal to {1, 1, 3). Round the nearest hundredth. (3) Find the magnitude of the orthogonal projection of i + j + 2k onto 2i 2j + k to the nearest hundredth. (4) When a constant force 13" acts on an object and causes the object to have a displace ment of d: the force is considered to have done work on the object, dened as the scalar quantity W = F\" - d: Determine the amount of work a force of 500 Newtons at an angle of 15 above the horizontal does in moving the 1 kg mass below up the 10 meter long incline (in Joules, the SI unit of energy). Round the nearest tenth. '111 6