If you'r referring to some objects, it means that the mass of the object is less than the water so it floats. If the mass of an object is greater than the mass of the water, it will sink. Compare it to a balloon, helium makes it rise, while normal air makes it sink.
Yes there is.
Momentum of an object is (its mass) times (its speed) .
Answer:
Change in potential energy is 700.7 J.
Explanation:
Given:
Mass of the object is, 
kg
Height to which the object is raised above his head, 
m
Acceleration due to gravity is, 
m/s²
We know that for a mass 
raised to a height 
, the change in potential energy is given as:
, where, 
Now, plug in the given values and solve.
Therefore, the change in the potential energy is 700.7 J.
Diffraction means spreading out of waves that has the same wavelength as the size of the gap. Sound waves have high wavelength and so it diffracts\spreads out and enables anyone to hear your voice from anywhere outside the room.
For inside the room, the sound waves doesn't actually diffract. They collide with the air particles, causing a series of compressions and rarefactions which spreads out in the air particles and anyone can hear your voice.
Air is the medium for the sound waves to travel.
Answer: C both A and B
Explanation:
Transmission : This simply implies the difference in rotation speed between the input shaft and output shaft. Note that higher gear ratios are used to transfer more torque, of which lower ratios trade torque is in favor of speed. Technician A was right
The primary functions of the transmission includes transmitting of the engines crankshaft into a more usable rotational speed and to multiply the torque of the engine's output. Hence,
Technician B was also right.
