Answer:
480.2 m
Explanation:
The following data were obtained from the question:
Speed of sound (v) = 343 m/s.
Time (t) = 2.8 s
Distance (x) of the cliff =?
The distance of the cliff from the woman can be obtained as follow:
v = 2x /t
343 = 2x /2.8
Cross multiply
2x = 343 × 2.8
2x = 960.4
Divide both side by the coefficient of x i.e 2
x = 960.4/2
x = 480.2 m
Therefore, the cliff is 480.2 m away from the woman.
Should be 8.7 m/s. Just divide 200 by 23 and round from there.
Answer : The number of half-life periods will be, 3
Explanation : Given,
Initial amount of lead = 10 kg
Amount of lead after decay = 1.25 kg
Half-life = 22 years
Formula used :

where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives
= half-life
Now put all the given values in the above formula, we get:




Thus, the number of half-life periods will be, 3
formula for wavelength = speed/frequency
So 1500/200 = 7.5 meters
Answer:
to produce electricty three ways you have the water wheel the wind mill and solor panels
Explanation: