L =47 m, Δy = h= 8 cm=0.08 m. V(x) = ?
h =g•t²/2, t = sqrt(2•h/g) =
= sqrt(2•0.08/9.8) =0.1278 s.
L =V(x) •t = > V(x) =L/t =
= 47/0.1278 =367.76 m/s.
V(y) - g•t = 9.8•0.1278 = 1.252 m/s.
V= sqrt[V(x)² + V(y)²] =
=sqrt[(367.76)²+ (1.252)²] =367.77 m/s.
A horizontal rifle is fired at a target 47 m away. The bullet falls vertically a distance of 8 cm on the way to the target.
(a) What is the speed of the bullet just after it left the rifle?
(b) What is the speed of the bullet just before it hits the target?
1 answer