Answer:
The velocity of the boy and the bicycle is 2.2 m/s.
Explanation:
We have,
Mass of child is 30 kg and the mass of bicycle is 20 kg. The combined momentum of the child and the bicycle is 110 kg-m/s.
It is required to find the velocity of the boy and the bicycle. The momentum of an object is given in terms of mass and its velocity. So,

M is combined mass of child and bicycle

So, the velocity of the boy and the bicycle is 2.2 m/s.
Answer:
A. Repeat the experiment to be sure the results are valid.
When air is blown across the top of an open <span>water bottle, air molecules in the bottle vibrate at a particular frequency and sound is produced in a process called "refraction".
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True it’s true because in the book it said all that stuff