Answer:
It helps us to know or be aware of some things that happen regular and teaches us about laws that guide us
Answer:
two separate forces
Explanation:
Electricity and magnetism are two separate forces. However, they come together in a field called electromagnetism. Both types of forces are linked; a moving magnet may push electric charges and trigger electric current. Objects which have both positive and negative charges are mutually repulsive to each other, and those with opposite charges are mutually attractive.
Answer:
the potentail of kinetic and potential energy
Explanation:
first explain the concept of kinetic energy (what it is and what its used for) and give examples (cars, a basketball thrown across a hall, and airplane), and do the same with potential energy (the energy an object stores, example: a streched rubber band)
Answer:
77.96dB
Explanation:
Recall that decibels are a unit of measuring intensity of sound, and depend on the logarithm of the intensity
the intensity, measured in decibels is given by:
I(db)=10log(I/I0)
I is the intensity in MKS units; I0 is the threshold intensity for human hearing (10^-12 W/m^2)
Thus, if the two sounds together have a dB of 81, we know:
81=10log(I/I0)
using the data above, we can find the intensity of the two sounds to be
0.000125 W/m^2
therefore, one firecracker has an intensity half of that, or 0.0000625W/m^2
now use this value to find the dB of one firecracker:
I(dB0=10log(0.0000625/10^-12)=77.96dB
Answer:
the second one Test the rate of decay of specific elements in rock samples.