Answer:
Actually it's 2.50 m/s, sorry
Explanation:
It is solved by using momentum conservation equation
combined mass of crow and feeder = 450+670=1120 gm
let the recoil speed of feeder be v m/s
Then applying momentum conservation we get;
1120×1.5 = 670×v
v= 2.50 m/s
the speed at which the feeder initially recoils backwards = 2.50 m/s
Answer:
Explanation:
Let's answer these statements
.1) True. This is the law of reflection.
.2) False. The speed of light depends on the index of refraction n = c / v
v = c / n
.3) True. The frequency creates a forced oscillation, whereby the atoms re-emit at the same incident frequency
.4) False. The index of refraction is a measure of the ratio of the speed of light in a vacuum and the material environment, the ability to change the trajectory is given by the law of refraction
.5) True. True due to the change in beam trajectory due to the law of refraction
.6 False. The phenomenon occurs when you pass from a medium with a higher index to one with a lower ratio, because the refracted beam separates from the normal
.7) True.
.8) False so that the lightning approach is valid Lam >> d,
.9) True.
Answer:
(a): The bird speed after swallowing the insect is V= 4.83 m/s
(b): The impulse on the bird is I= 0.3 kg m/s
(c): The force between the bird and the insect is F= 20 N
Explanation:
ma= 0.3 kg
va= 6 m/s
mb= 0.01kg
vb= 30 m/s
(ma*va - mb*vb) / (ma+mb) = V
V= 4.83 m/s (a)
I= mb * vb
I= 0.3 kg m/s (b)
F*t= I
F= I/t
F= 20 N (c)
Answer:
(a) 0 (b) 
Explanation:
Given that,
Mass of a supertanker, 
The engine of a generate a forward thrust of, 
(a) As the supertanker is moving with a constant velocity. We need to find the magnitude of the resistive force exerted on the tanker by the water. It is given by :
F = ma, a is the acceleration
For constant velocity, a = 0
So, F = 0
(b) The magnitude of the upward buoyant force exerted on the tanker by the water is equal to the weight of the ship.
F = mg

Hence, this is the required solution.
Answer:
Option a)
Explanation:
In the process of charging anything by the method of induction, a charged body is brought near to the body which is neutral or uncharged without any physical contact and the ground must be provided to the uncharged body.
The charge is induced and the nature of the induced charge is opposite to that of the charge present on the charged body.
So when a positively charged rod is used to charge an electroscope, the rod which is positive attracts the negative charge in the electroscope and the grounding of the electroscope ensures the removal of the positive charge and renders the electroscope negatively charged.