Answer:
t=4.86s
Explanation:
To find the wavelength you use the following formula:

v: speed of sound = 343m/s
f: frequency = 400Hz
λ: wavelength of the sound
By doing λ the subject of the formula and replacing the values of f and v you obtain:

Now, to calculate the time that sound takes to reach the last row you use:

t: time
d: distance to the last row = 1947m

hence, the time is 4.86s
Rust, photosynthesis, and heat from fire are all chemical reactions <span>because </span>new substances are formed and the chemical formula is changed. By doing this, bonds are broken and formed in the making of the new substance. Melting ice is physical change the molecules are still water molecules, it just changed physical form.
Answer:
E = 2.7 x 10¹⁶ J
Explanation:
The release of energy associated with the mass can be calculated by Einstein's mass-energy relation, as follows:

where,
E = Energy Released = ?
m = mass of material reduced = 0.3 kg
c = speed of light = 3 x 10⁸ m/s
Therefore,

<u>E = 2.7 x 10¹⁶ J</u>
Answer:
She run for, t = 0.92 s
Explanation:
Given data,
The velocity of the runner, v = 10 km/h
The distance covered by the runner, d = 9.2 km
The relationship between the velocity, displacement and time is given by the formula,
t = d / v
Substituting the given values in the above equation,
t = 9.2 / 10
= 0.92 s
Hence, she ran for, t = 0.92 s
Answer:
the question this morning
Explanation:
90+70 look than