Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
Answer:
The rise in height of combined block/bullet from its original position is 0.45m
Explanation:
Given;
mass of bullet, m₁ = 12 g = 0.012 kg
mass of block of wood, m₂ = 1 kg
initial speed of bullet, u₁ = 250 m/s.
initial speed of block of wood, u₂ = 0
From the principle of conservation of linear momentum, calculate the final speed of the combined block/bullet system.
m₁u₁ + m₂u₂ = v(m₁+m₂)
where;
v is the final speed of the combined block/bullet system.
0.012 x 250 + 0 = v (0.012 + 1)
3 = v (1.012)
v = 3/1.012
v = 2.96 m/s
From the principle of conservation of energy, calculate the rise in height of the block/bullet combined from its original position.
¹/₂mv² = mgh
¹/₂v² = gh
¹/₂ (2.96)² = (9.8)h
4.3808 = 9.8h
h = 4.3808/9.8
h = 0.45 m
Therefore, the rise in height of combined block/bullet from its original position is 0.45m
Both bricks will hit the ground at the same time.
Falling vertically is always accelerating at 9.8 m/s² because of gravity.
Nothing that's happening horizontally has any effect on that.
The brick that happens to have some horizontal motion will
probably hit the ground way over there, but that will still be
at the same TIME as this one.
This is a perfect place to remind you of the old unbelievable story,
which I'll bet you heard before:
If you fire a bullet horizontally from a gun, and at the exact same
moment you DROP another bullet out of your hand next to the gun,
the two bullets will hit the ground at the same time ! Even though
they'll be far apart.
Horizontal speed has no effect on vertical behavior.
When the temperature lowers the plants can freeze and die. One way to prevent that is to cover the plants so they dont freeze
Answer:
1. telescope
2.
f- focal length
f- focal length r- the radius of curvature of the mirror
p-the distance of the object from the vertex of the mirror
l-the distance of the figure from the vertex of the mirror
