Answer:
The speed is constant.
Speed is a scalar quantity (magnitude only).
Velocity is a vector quantity (magnitude and direction).
For an object in Uniform Circular Motion the change in velocity is always
directed towards the center of the circle, and this change of velocity
gives rise to the acceleration which is directed towards the center of
rotation. This is called the centripetal acceleration, and it is the centripetal
force (for instance the attraction of the moon towards the earth) which
produces the centripetal acceleration.
Answer:
Explanation:
Let the angle between the first polariser and the second polariser axis is θ.
By using of law of Malus
(a)
Let the intensity of light coming out from the first polariser is I'
.... (1)
Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.
By the law of Malus
So,
(b)
Now differentiate with respect to θ.
Answer:
Power = 377.35 W or Power = 0.5065 hp
Explanation:
Given:
Number of steps, n = 1576
height of each step, h = 0.20 m
Total height achieved, H = nh = 1576 × 0.20 = 315.2 m
Mass of the runner, M = 70.0 kg
Total time taken, t = 9 minutes 33 seconds = (9 × 60) + 33 = 573 seconds
Now, the potential energy gained by the runner,
E = MgH
where, g is the acceleration due to the gravity
on substituting the values in the above formula, we get
E = 70 × 9.8 × 315.2
or
E = 216227.2 J
also,
Energy = Power × time
therefore,
Power = Energy/time
or
Power = 216227.2 J / 573
or
Power = 377.35 W
Now,
745 watt = 1 hp
or
1 watt = 1/745 hp
thus,
Power = 377.35 W = 337.35 × (1/745) hp
or
Power = 0.5065 hp
