146. A shell travelling with a horizontal velocity of 100 m/sec explodes and splits into two parts, one of mass 10 kg and the other of 15 kg. The 15 kg mass drops vertically downward with initial velocity of 100 m/sec and the 10 kg mass begins to travel at an angle to the horizontal of tan”1 x, where x is______________________?

A. 3/4
B. 4/5
C. 5/3
D. 3/5
✅ The correct answer is option D.

147. Higher pitch of the roof (1) results in stronger roof (2) results in weaker roof (3) requires more covering material (4) requires less covering material The correct answer is___________?

A. (1) and (3)
B. (1) and (4)
C. (2) and (3)
D. (2) and (4)
✅ The correct answer is option A.