Answer:
Part a)

Part b)
T = 4.68 s
Explanation:
Part a)
Shell is fired at speed of 40 m/s at angle of 35 degree
so here we have


since gravity act opposite to vertical speed of the shell so at the highest point of its trajectory the vertical component of the speed will become zero
so at the highest point the speed is given

Part b)
After completing the motion we know that the displacement of the object will be zero in Y direction
so we have




106.68 centimetres are in 3.50 feet
Frost will disturb the smooth flow of air over the wing, unpleasantly
distressing its lifting competence. In other words, this spoils the even flow
of air over the wings, by this means decreasing lifting capability. Also, frost
may avoid the airplane from becoming flying at normal departure speed.
F = m • a
What we know:
- Gravity: 9.8 m/s
- Force: 490 N
Equation derived:
m = F/a
m = 490/9.8
= 50 kg
Any of the above depending on the direction of forces