Answer:
Mass of bike = 38 kg.
Explanation:
Kinetic energy is given by the expression,
, where m is the mass and v is the velocity.
Here speed of child riding bike = 6 m/s
Mass of child = 30 kg
Total kinetic energy = 1224 J
Let the mass of bike be, m kg
So, total mass of child and bike = (m + 30) kg
Substituting,

So, mass of bike = 38 kg.
Solution:
Make an Observation - An indoor plant in a dark room withers faster than the same plant in a room with ample sunlight.
Ask a question- Why do certain indoor plants die faster based on where they are placed in the house?
State a hypothesis- Sunlight is probably essential for plants to grow and live.
Run an experiment- Get two potted plants. Cover one with black paper. Place both plants outside in sunlight. See what happens to each plant after one week.
Analyze the results-The plant in the pot with black paper withered. The other plant was healthy.
Communicate the results to others - Plants need sunlight to make food so they can live.
<em>Hello there, and thank you for asking your question here on brainly.
<u>Answer: Koala bears are considered herbivores, or as in the scientific name, arboreal herbivorous marsupial, marsupial because it also carries it's babies around in a pouch. Koala bears are also native to Australia, which eucalyptus leaves are also native to.
</u>
Hope this helped you! ♥</em>
Answer:
The correct answer is option 'd': The frequency decreases and the intensity of the sound decreases.
Explanation:
1) <u>Effect on Frequency </u>
According to Doppler's effect of sound we have
for a source of sound moving away from the observer the relation between the observed and the original frequency is given by

where
c = speed of sound in air
is the velocity of observer of sound
is the velocity of source of sound
is the original frequency of sound
As we see the ratio is less than 1 thus the frequency of sound that the observer receives is less than that of source.
2) <u>Effect on Intensity:</u>
At a distance 'r' from source emitting a wave of Power 'P' is given by

As we see on increasing 'r' intensity of sound decreases.