Yes. sound waves are produced by energy.
The law says things travel in a straight line at constant speed unless acted upon by a force. But friction is a force but it can't be seen easily other than its effect, which is to bring the object to rest in seeming violation of the 1st law.
The longest wavelength in the Molecule's absorption spectrum is 2250nm
The kinetic energy of an object of mass m and velocity v is given by
Let's call
the initial speed of the car, so that its initial kinetic energy is
where m is the mass of the car.
The problem says that the car speeds up until its velocity is twice the original one, so
and by using the new velocity we can calculate the final kinetic energy of the car
so, if the velocity of the car is doubled, the new kinetic energy is 4 times the initial kinetic energy.
Answer:
B) 4500 Pa
Explanation:
As pressure is force per unit area,
P = F/A
It stands to reason that the smallest pressure for a given force is when it is shared by the largest area.
The possible areas are
0.30(0.40) = 0.12 m²
0.30(0.50) = 0.15 m²
0.40(0.50) = 0.20 m²
The pressure when the face with the largest area (0.20 m²) is down is
P = 900 / 0.20 = 4500 N/m² or 4500 Pa
the other possible pressures would be
900/0.15 = 6000 Pa
900/0.12 = 7500 Pa
which are both larger than our solution.