Answer:
C. Burning coal tends to harm the environment more than using solar panels.
Explanation:
When coal is burned, it reacts with the oxygen in the air. This reaction converts the stored potential energy, which turns into thermal energy, which is released as heat. But it also produces methane and carbon dioxide which is released into the air.
Answer:
(D) a brief early period of hyper rapid expansion of space-time.
Explanation:
Cosmic inflation is a theory which states that in an interval of 10⁻³⁶ seconds to around 10⁻³³ seconds after the big bang there was a massive expansion.
According to the big bang theory the universe came to be from a singularity i.e., a point of infinite gravitational field. The universe is expanding this means that according to the conservation of energy the universe was expanding from the beginning.
Energy is transferred in a wave
Energy is transferred, but mass is not.
Scalar is a quantity such as mass or length that is completely determined by its own magnitude and has no direction. Therefore, your answer is Speed.
Answer:
a) 665 kg.m/s
b) 2.97 kN
Explanation:
The impulse is given by:
where
va=velocity after
vb=velocity before
The velocity just before is given by:
The velocity just after is zero because there wasn't a rebound.
So the impulse is:
The impulse is also given by:
