The speed of sound is greater in ice (4000 m/s), then in water (1500 m/s), then in air (340 m/s). The explanation for this is the differente state of the matter in the three cases.
In fact, sound waves travel faster in solids (like ice), then in liquids (like water), then in gases (like air). This is because the speed of the sound wave depends on the density of the medium: the greater the density, the faster the sound wave. This can be easily understood by thinking at how a sound wave propagates: a sound wave is a vibration of molecules, which is transmitted throughout the medium by collision of the molecules. Therefore, the smaller the spacing between the molecules (such as in solids), the more efficient is the propagation, and so the sound wave is faster. On the contrary, there is a large spacing between molecules in gases (such as in the air), so there are less collisions between the molecules and so the wave is not transmitted efficiently, and so it has less velocity.
Answer:
B) 2.7 g of aluminium has a volume of 1 cm^3
Explanation:
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;

If the density of aluminum is 2.7 g/cm³, it simply means that 2.7 g of aluminium has a volume of 1 cm³
Check:
Given the following data;
Mass = 2.7 grams
Volume = 1 cm³
Substituting into the formula, we have;

Density = 2.7 g/cm³
Answer:
The amount of potential energy that was initially stored in the spring is 88.8 J.
Explanation:
Given that,
Mass of block = 1.60 kg
Angle = 30.0°
Distance = 6.55 m
Speed = 7.50 m/s
Coefficient of kinetic friction = 0.50
We need to calculate the amount of potential energy
Using formula of conservation of energy between point A and B



Put the value into the formula


Hence, The amount of potential energy that was initially stored in the spring is 88.8 J.
Answer: its a strip of transparent film, one side coated with gelatin emulsion containing microscopically small light-sensitive silver halide crystals
Explanation: