4896
0.85 x 45 x 128 = 4896
Change in energy = specific heat capacity x mass x change in temperature
Answer:
v = 7.95 m/s
Explanation:
Given that,
Wavelength of a wave, 
Frequency of a wave, f = 15 Hz
We need to find the speed of the wave. The speed of a wave is given by :

So, the wave move with a speed of 7.95 m/s.
Answer:
Friction:-
The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. There are at least two types of friction force - sliding and static friction. Though it is not always the case, the friction force often opposes the motion of an object. For example, if a book slides across the surface of a desk, then the desk exerts a friction force in the opposite direction of its motion. Friction results from the two surfaces being pressed together closely, causing inter molecular attractive forces between molecules of different surfaces. As such, friction depends upon the nature of the two surfaces and upon the degree to which they are pressed together. The maximum amount of friction force that a surface can exert upon an
EG:-
A coaster sliding against a table.
Gravity:-
The force of gravity is the force with which the earth, moon, or other massively large object attracts another object towards itself. By definition, this is the weight of the object. All objects upon earth experience a force of gravity that is directed "downward" towards the center of the earth. The force of gravity on earth is always equal to the weight of the object as found
EG:-
The force that causes a car to coast downhill even when you aren't stepping on the gas.
Elastic:-
Elasticity is the ability of a material to return to its original shape after being stretched or compressed. When an elastic material is stretched or compressed, it exerts elastic force. This force increases the more the material is stretched or compressed.
EG:-
An archer's stretched bow
Answer:
The wavelength of the EM wave is 7.5 * 10⁻⁴ m
Explanation:
The velocity of a wave is related to its wavelength by the following formula;
velocity = wavelength * frequency
For an electromagnetic (EM) wave, its velocity is equal to the velocity of light, c = 3.0 * 10⁸ m/s
Given that the frequency and veloity of the given EM wave in the question is known, its wavelength is calculated as follows:
wavelength = velocity/frequency
where velocity of the EM wave = 3.0 * 10⁸ m/s;
frequency = 4THz = 4 * 10¹² Hz
wavelength = 3.0 * 10⁸m/s / 4 * 10¹² Hz
wavelength = 7.5 * 10⁻⁴ m
Therefore, the wavelength of the EM wave is 7.5 * 10⁻⁴ m