Answer:
Kaleidoscope operates on the principle of multiple reflection.
Construction of a kaleidoscope:
1. A kaleidoscope is constructed using three narrow strips of plane mirrors inclined at angles of 60° enclosed in a tube.
2. One end of tube has a ground glass plate with a clear glass plate on its inner side.
3. A metallic ring separates the two plates and the space is filled with coloured pieces of glass or broken bangles.
4. A cardboard with a hole in the centre is fixed on the other end of the tube.
Answer:
The bullet accelerates more than the gun
Explanation:
The forward momentum of a bullet is the same as the backward momentum of the gun, but it is more dangerous to be hit by the gun than by the bullet because the velocity of the bullet after the gun was fired will be much more than the velocity of the gun going backwards. That's because the gun has a bigger mass and therefore a smaller acceleration while the bullet has a smaller mass and therefore a bigger acceleration.
Answer:
Explanation:
According to Ohm's law:
Where:
is the voltage difference across the light bulb
is the resistance of the light bulb (the value we want to find)
is the electric current
Isolating
:
Finally:
This is the resistance of the light bulb
When wool cloth loses electrons, there'll be excess of protons left in wool. Hence option A is correct.
Answer:
MR²w²
Explanation:
Given:
Mass of the hoop = M
Radius of the hoop = R
Angular velocity of the wheel = w
Since, the hoop is rolling without slipping
thus,
Total kinetic energy = Rotational Kinetic energy + Translation Kinetic Energy
or
The total kinetic energy = ![\frac{1}{2}Iw^2+\frac{1}{2}Mv^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7DIw%5E2%2B%5Cfrac%7B1%7D%7B2%7DMv%5E2)
here,
I is the moment of inertia of the hoop
I = MR²
v is the translational speed of the wheel
also,
v = Rw
therefore,
the total kinetic energy = ![\frac{1}{2}MR^2w^2+\frac{1}{2}M(Rw)^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7DMR%5E2w%5E2%2B%5Cfrac%7B1%7D%7B2%7DM%28Rw%29%5E2)
or
The total kinetic energy = MR²w²