If the echo (the reflected sound) reaches your ear less than about
0.1 second after the original sound, your brain doesn't separate them,
and you're not aware of the echo even though it's there.
If the echo comes from, say, a wall, 0.1 second means you'd have to be
about 17 meters away from the wall. If you're closer than that, then the
echo reaches you in less than 0.1 second and you're not aware of it.
A. 30 meters . . .
No. You hear that echo easily
B. you're standing within range of both sounds . . .
No. You hear that echo easily, if you're at least 17 meters from the wall.
C. less than 0.1 second later . . .
That's it. The echo is there but your brain doesn't know it.
D. 21.5 meters
No. You hear that echo easily.
The basis for Rutherford's Planetary model, was the results he got from experiments.
He observed that most of the alpha particles he fired at a gold foil, passed through the foil, but only few were deflected back. So he concluded that most of the Atom would be empty space, with a positive entity at the center.
The average power is 10 watts. What's the question ?
Answer:
I think option A is correct
=> it increases the initial energy of the reactants
hope it helps
Answer:
The final position made with the vertical is 2.77 m.
Explanation:
Given;
initial velocity of the ball, V = 17 m/s
angle of projection, θ = 30⁰
time of motion, t = 1.3 s
The vertical component of the velocity is calculated as;
The final position made with the vertical (Yf) after 1.3 seconds is calculated as;
Therefore, the final position made with the vertical is 2.77 m.
