<span>A warranty is an offer to repair or replace a product if there is a problem with the product. Warranties are written guarantee issued to the consumer by the manufacturer at the time of purchase, promising to repair or replace a faulty material. It is usually based on the premise that the product is free from defects in materials and workmanship. It claims that the manufacturer constructed the product out of proper materials, and would compensate the consumer should there be any defects. The period to file a claim typically varies. Some manufacturers place a 90 day period, some a year and a few, even more.</span>
Da Vinci was fascinated by how timepieces operate. Based on one of his sketches, it uses the laws of motion and a vertical "flying" pendulum escapement to keep accurate time.
The pendulum's weights, in a bucket suspended from a crane-style arm, act as the clock's power source. The weights propel the pendulum from vertical post to vertical post. As it "flies" it turns precision gears, which in turn keep time. To speed up or slow the clock, adjust the weight-balance of the pendulum by adding or removing weights.
Answer:
b) the refracted ray has an angle of 90 degrees
Explanation:
The angle of incidence is measured with respect to the normal separation of the media. The critical angle for total internal reflection occurs is:
Here 
and 
are the refractive index of the mediums. This equation is an application of Snell's law, for the case where the refracted ray has an angle of 
.
