Answer:
y = 27 cm
Explanation:
given,
After 11 hours of burning height of candle is 27.9 cm
After 30 hours of burning height of candle is 26 cm
height after 20 hour = ?
the candle height decreases linearly
using linear equation
y = m x+ c
27.9 = m (11 ) + C.......(1)
26 = m (30) + C..............(2)
on solving equation (1) and (2)
1.9 = -19 m
m = -0.1
from equation 2
26 = -3 + C
C = 29
y = m x + 29
at 20 hour
y = -0.1× 20 + 29
y = 27
height of candle after 20 hours is 27 cm.
Electromagnetic radiation in order of increasing (lowest to highest) frequency is Radio waves < Green visible light < UV radiation.
<h3>What is Frequency?</h3>
This is defined as the rate at which something occurs or is repeated over a particular period of time. The unit of frequency is referred to as Hertz.
Electromagnetic radiations with increasing frequency can be seen below:
Radio waves, microwaves, infrared waves, visible light, ultraviolet radiations, X rays, γ rays.
Read more about Frequency here brainly.com/question/254161
Three of the statements are true. 'D' is false.
Glass and rubber are excellent insulators, total duds as conductors.
Answer
(C).
When there is an angle between the two directions, the cosine of the angle must be considered.
Step by step Solution
The work done by a force is defined as the product of the force and the distance traveled in the direction of motion.
The first answer "Only the component of the force perpendicular to the motion is used to calculate the work" is wrong because, the force perpendicular to motion does no work.
The second choice "If the force acts in the same direction as the motion, then no work is done" is wrong because the work in the direction of the force is 
.
Fourth answer "A force at a right angle to the motion requires the use of the sine of the angle" is wrong because the 
meaning that there is no work done in the direction perpendicular to the motion.
The third answer" When there is an angle between the two directions, the cosine of the angle must be considered." is correct because the work is calculated using the force in the direction of the motion. The magnitude of this force is 
