The horizontal speed has no effect on the answer.
It doesn't matter whether you flick a marble horizontally from the roof,
fire a high-power rifle horizontally from the roof, drive a school bus straight
off the roof, or drop a bowling ball from the roof with zero horizontal speed.
Their vertical speed is completely determined by gravity, (and it happens to
be the same for all of them).
Handy dandy formula for the distance covered by anything that starts out
with zero speed and accelerates to the end:
Distance = (1/2) (acceleration) x (time)²
If the beginning of the journey is on Earth, then the acceleration is
9.8 m/s² ... the acceleration of gravity on Earth. We'll assume that
the 55-meter rooftop in the question is part of a building on Earth.
55 meters = (1/2) (9.8 m/s²) x (time)²
Divide each side
by 4.9 m/s² : 55 m / 4.9 m/s² = (time)²
(time)² = (55/4.9) sec²
Square-root
each side: time = √(55/4.9 sec²)
= 3.35 sec .
Answer:
<h2>a) Time elapsed before the bullet hits the ground is 0.553 seconds.</h2><h2>b)
The bullet travels horizontally 110.6 m</h2>
Explanation:
a) Consider the vertical motion of bullet
We have equation of motion s = ut + 0.5 at²
Initial velocity, u = 0 m/s
Acceleration, a = 9.81 m/s²
Displacement, s = 1.5 m
Substituting
s = ut + 0.5 at²
1.5 = 0 x t + 0.5 x 9.81 xt²
t = 0.553 s
Time elapsed before the bullet hits the ground is 0.553 seconds.
b) Consider the horizontal motion of bullet
We have equation of motion s = ut + 0.5 at²
Initial velocity, u = 200 m/s
Acceleration, a = 0 m/s²
Time, t = 0.553 s
Substituting
s = ut + 0.5 at²
s = 200 x 0.553 + 0.5 x 0 x 0.553²
s = 110.6 m
The bullet travels horizontally 110.6 m
Answer:
Explained
Explanation:
Resistance R in a current flow through an object is given by
ρ = resistivity of the material
L= length of the object
A= area of cross section
clearly resistance is directly dependent on length of the object.This means greater the length larger will be resistance to current.
thermal resistance R_th is given by
L= length of the object
A= area of cross section
K = Conductivity of the material
thermal resistance is also is directly dependent on length of the object.This means greater the length larger will be resistance to current.
The answer is attract. Hope it helps! :)
Answer:
T = 4 sec / 2 = 2 sec period of revolution
S = 2 pi R = 2 * pi * 1.75 m = 11 m
V = S / T = 11 m / 2 sec = 5.5 m/s speed of object
