Answer: Option (A) is the correct answer.
Explanation:
Laser helps in zooming an image on which it is directed or falls so that it becomes easier for a large population to understand what the teacher or guide is talking about.
For example, when Greg is giving slide show presentation to a large audience then in order to make his slides visualized by everyone in the room he uses laser.
Therefore, we can conclude that a laser best help him with the presentation as he can use the laser to enlarge images on the slides.
Answer:
ANSWER BELOW I
I
V
Remember that w=mg where w is weight in Newtons, m is mass in kilograms, and g is gravity in
m/s2
. For example, for Earth, 445 N = 45.4 × 9.8
m/s2
:Notice that the x-axis values will be gravity in
m/s2
, which is already given in the table, and the y-axis values will be the weight in Newtons. Remember to round your weights to a whole number, and to enter the points starting with the lowest gravity (moon, then Mars, then Venus, then Earth).
Answer:
a)
, b)
, c) 
Explanation:
a) The net torque is:

Let assume a constant angular acceleration, which is:



The moment of inertia of the wheel is:



b) The deceleration of the wheel is due to the friction force. The deceleration is:



The magnitude of the torque due to friction:


c) The total angular displacement is:



The total number of revolutions of the wheel is:



Answer:
1.97 x 10^8 m/s
Explanation:
refractive index of crown glass with respect to air, n = 1.52
speed of light in air, c = 3 x 10^8 m/s
Let v be the speed of light in crown glass.
By use of the definition of refractive index

where, n be the refractive index of crown glass, c be the speed of light in vacuum and v be the speed of light in crown glass


v = 1.97 x 10^8 m/s
Thus, the speed of light in crown glass is 1.97 x 10^8 m/s.