Data:
F = 150 N
a = 5 m/s^2 (I corrected the units of acceleration)
m = ?
Formula: F = m*a (second Law of Newton).
Solution:
F = m*a => m = F / a
=> m = 150 N / 5 m/s^2 = 30 kg
Answer: the combined mass of the tricycle and toddler is 30 kg.
This is an incomplete question, here is a complete question.
According to the EPA, the maximum contaminant level (MCL) of antimony in drinking water is 0.0060 mg/L.
Convert the MCL of antimony from milligrams per liter to parts per billion (ppb).
Answer : The maximum contaminant level (MCL) of antimony in drinking water in parts per billion is, 6 ppb
Explanation :
ppb : It is defined as the mass of solute present in per 1000 million
of total mass.
1 ppb = 
As we know that:
1 milligrams per liter = 1000 parts per billion
or,
1 mg/L = 1000 ppb
As, 1 mg/L = 1000 ppb
So, 0.0060 mg/L = 
= 6 ppb
Thus, the maximum contaminant level (MCL) of antimony in drinking water in parts per billion is, 6 ppb
B because you can feel the current
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