Answer:
14 m/s
Explanation:
Using the principle of conservation of energy, the potential energy is converted to kinetic energy, assuming any losses.
Kinetic energy is given by ½mv²
Potential energy is given by mgh
Where m is the mass, v is the velocity, g is acceleration due to gravity and h is the height.
Equating kinetic energy to be equal to potential energy then
½mv²=mgh
V
Making v the subject of the formula
v=√(2gh)
Substituting 9.81 m/s² for g and 10 m for h then
v=√(2*9.81*10)=14.0071410359145 m/s
Rounding off, v is approximately 14 m/s
Answer:
The Laws of Badminton
A match consists of the best of 3 games of 21 points.
Every time there is a serve – there is a point scored.
The side winning a rally adds a point to its score.
At 20 all, the side which gains a 2 point lead first, wins that game.
At 29 all, the side scoring the 30th point, wins that game.
Answer:
(a) Angle of incidence for violet is more than the angle of incidence for red
(b) 2.4°
Explanation:
refractive index for violet , v = 1.66
refractive index for red, nR = 1.61
wavelength for violet, λv = 400 nm
wavelength for red, λR = 700 nm
Angle of refraction, r = 30°
(a) Let iv be the angle of incidence for violet.
Use Snell,s law
nv = Sin iv / Sin r
1.66 = Sin iv / Sin 30
Sin iv = 0.83
iv = 56°
Use Snell's law for red
nR = Sin iR / Sin r
where, iR be the angle of incidence for red
1.61 = Sin iR / Sin 30
Sin iR = 0.805
iR = 53.6°
So, the angle of incidence for violet is more than red.
(b) iv - iR = 56° - 53.6° = 2.4°
When the bus starts moving forward, the man remains at rest,
causing him to lean back.
When the bus slows down, the man continues to move forward,
and appears to lean forward.
Both events are examples of the effect of inertia.
