Answer:
Explanation:
2. A compression wave, like sound, is a kind of <u>mechanical</u> wave.
3. When a wave reflects off a surface, the angle of <u>incidence</u> always equals the angle of <u>reflection</u>.
4. The wailing change of the pitch that you hear as a locomotive approaches and then recedes from you is called <u>Doppler Shift</u>.
I believe the correct answer from the choices listed above is option B. In a food chain. it is the producers trophic level that contains <span>the greatest amount of energy since it is the very start of the chain. Most of the energy are being stored and passed to the next organism. Hope this answers the question.</span>
Answer:
height is 69.68 m
Explanation:
given data
before it hits the ground = 46 % of entire distance
to find out
the height
solution
we know here acceleration and displacement that is
d = (0.5)gt² ..............1
here d is distance and g is acceleration and t is time
so when object falling it will be
h = 4.9 t² ....................2
and in 1st part of question
we have (100% - 46% ) = 54 %
so falling objects will be there
0.54 h = 4.9 (t-1)² ...................3
so
now we have 2 equation with unknown
we equate both equation
1st equation already solve for h
substitute h in the second equation and find t
0.54 × 4.9 t² = 4.9 (t-1)²
t = 0.576 s and 3.771 s
we use here 3.771 s because 0.576 s is useless displacement in the last second before it hits the ground is 46 % of the entire distance it falls
so take t = 3.771 s
then h from equation 2
h = 4.9 t²
h = 4.9 (3.771)²
h = 69.68 m
so height is 69.68 m
Answer:
312,497.5Joules
Explanation:
Work done = force × distance
W = FS
Get the force
F = ma
F = 1250×9.8
F = 12250N
Get the distances using the equation of motion
v² = u² +2gS
30² =20²+2(9.8)S
900 =400+19.6S
900-400 =19.6S
500 = 19.6S
S = 500/19.6
S = 25.51m
Get the work done
Work done = 12250×25.51
Workdone = 312,497.5Joules
