Answer:
a) t = 5.40 s
b) 
c) 
d) mv = 74.6 kgm/s
Explanation:
<u>We have</u>:
v₀ : initial speed = 45.6 m/s
θ: 30 °
h: height = 20 m
m: projectile's mass = 1.5 kg
a) The flight time of the projectile as it lands at Q (when it impacts on the ground in the parabolic motion) can be calculated using the following equation:
(1)
Where g is the gravity = 9.81 g/s²
By solving equation (1) for t, we have:
b) The gravitational potential energy (
) of the projectile at point P (at the maximum height in the parabolic motion) is the following:
Where 
: is the height at the point P. This can be calculated using the following equation:
Now, the gravitational potential energy is:
c) The kinetic energy of the projectile at point R (the same height as the edge of the building in the parabolic motion) is:
Where 
is the velocity at the point R, which is:
Now, the kinetic energy is:
d) The magnitude and direction of impulse the projectile impacts on the ground can be calculated using the equation:
Where F: is the force
The velocity at the point Q is:
Hence, the magnitude and direction of impulse is:
I hope it helps you!
