A gunman standing on a sloping ground fires up the slope. The initial speed of the bullet is v0= 390 m/s. The slope has an angle α= 25 degrees from the horizontal, and the gun points at an angle θ from the horizontal. The gravitational acceleration is g=10 m/s2.

Question

(a) For what value of θ ( where θ>α) does the gun have a maximal range along the slope? (in degrees, from the horizontal)

θ=

(b) What is the maximal range of the gun, lmax, along the slope? (in meters)

lmax=

Answer 1

a)
Without an incline the ideal angle would be pi/4 = 45°

to get theta:
(90/2)+(α/2)

b)
since there is an incline we have to consider the angle α
(1−sinα)*v0^2/(g*cos^2(α))

Answer 2

http://cnx.org/content/m14614/latest/

Answer 3

Thank you, Elena!