Answer:
Explanation:
Speed of the source of sound = v = 44.7 m/s
Speed of sound = V = 343 m/s
a) Apparent frequency as the train approaches = f = [V /(V -v) ] × f
= [343 / (343 - 44.7) ] × 415 = 477.18 Hz
Wave length = λ = v / f = 343 / 477.18 = 0.719 m
b) Frequency heard as the train leaves = f ' = [V / ( V + v) ] f
= [343 / { 343 + 44.7 ) ] x 415
= 367.2 Hz
Wavelength when leaving = v / f = 343 / 367.2 = 0.934 m
Pretty sure the answer is C. Screw: wheel and axle
3NaOH + FeCl3 → 3NaCl + Fe(OH)3
Answer:
Explanation:
Work done on the lever ( input energy ) = force applied x input distance
= 24 N x 2m = 48 J
Work done by the lever ( output energy ) = load x output distance
= 72 N x 0.5m = 36 J
efficiency = output energy / input energy
= 36 J / 48 J
= 3 / 4 = .75
In percentage terms efficiency = 75 % .
Answer:
<h2>The pin's final velocity is 5m/s</h2>
Explanation:
Step one:
given data
mass of ball m1=5kg
initial velocity of ball u1=10m/s
mass of pin m2=2kg
initial velocity of pin u2= 0m/s
final velocity of ball v2=8m/s
final velocity of pin v2=?
Step two:
The expression for elastic collision is given as
m1u1+m2u2=m1v1+m2v2
substituting we have
5*10+2*0=5*8+2*v2
50+0=40+2v2
50-40=2v2
10=2v2
divide both sides by 2
v2=10/2
v2=5m/s
The pin's final velocity is 5m/s
