A bullet is fired in a horizontal direction with a muzzle velocity of 300m\s in the absence of air resistance,how far will it have dropped in travelling a horizontal distance of (a)20m (b)40m (c)60m (d)how far will it drop in one second

9 answers

In 20m that is 60s 40m is 7.5s 60m is 50s in one second is 300m
a. Dx = Xo*t. t = Dx/Xo = 20/300 = 0.067 s.
Dy = 0.5g*t^2 = 4.9*0.067^2 = 0.022 m.

b. t = d/Vo = 40/300 = 0.133 s.
Dy = 4.9*0.133^2 = 0.087 m.

c. t = Dx/Vo = 80/300 = 0.267 s.
Dy = 4.9*0.267^2 = 0.348 m.

d. Dy = 4.9*1^2 = 4.9 m.
I don't understand
Please explain
Them
(a) S = ut+1/2at² (a=0)
S=ut
t= s/u
t= 20/300
t= 0.067 sec

h= ut+1/2gt² ( u=0)
h= 1/2*5*(0.067)²
h= 0.022 m

(b)s should be equal to 40m
(c) S = 60m

(d) h=ut+1/2gt² (u=0)
h=1/2gt² (g=9.8 or 10)
h= 1/2*9.8*1
h= 4.9m ( if g=10, h=5m)
Tank u
Explain better please
Number b and c u did not explain them
How do you get 4.9
20×3=