Answer:
scratching a surface to make it rougher
increasing the size of a flying object
adding extra weight to an object
Explanation:
dimension = 30.0 m ✕ 15.0 m ✕ 5.0 m.
density = 1.20 kg/m3
(a)volume = lenght * breadth * height
= 30 * 15 * 5
= 2250 metre cube = 2.25 cubic meter
(b) mass of air = density * volume
mass of air = 1.2 * 2250
mass of air = 2700kg
weight = mass * 9.8
= 2700 * 9.8
= 26,460 N
- The definition of Density is the amount of matter in a given space, or volume
- Density = mass/volume
- units for density kg/m^3
- Density of water 1g/ml
- Salt water is denser that is why don't sink as easily.
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Work in general is given by W=F·d where F is the force vector and d is the displacement vector. The dot symbol is the dot product which is a measure of how parallel two vectors are. It can be replaced by the cosine of the angle between the two vectors and the vectors replaced by their magnitudes. If F and d are parallel then the angle is zero and the cosine is unity. So in this case work can be defined as the product of the magnitudes of the force and distance:
W=Fd
Explanation:
(a)
Critical angle is the angle at the angle of refraction is 90°. After the critical angle, no refraction takes place.
Using Snell's law as:
Where,
is the angle of incidence
is the angle of refraction = 90°
is the refractive index of the refraction medium
is the refractive index of the incidence medium
Thus,
The formula for the calculation of critical angle is:
Where,
is the critical angle
(b)
No it cannot occur. It only occur when the light ray bends away from the normal which means that when it travels from denser to rarer medium.
U=1/2kx2
This image sums it up