Answer:
<em>The distance covered by comet is </em>
Explanation:
Speed is defined as the rate of change of distance with time. It is given by the equation speed= 
Thus distance= 
In this problem it is given that speed of comet= 
time travelled by the comet= 4 hours
Thus distance= 
= 
= 
Answer:
The image height is 3.0 cm
Explanation:
Given;
object distance,
= 15.0 cm
image distance,
= 5.0 cm
height of the object,
= 9.0 cm
height of the image,
= ?
Apply lens equation;

Therefore, the image height is 3.0 cm. The negative values for image height indicate that the image is an inverted image.
Explanation:
The triple beam balance is used to measure masses very precisely; the reading error is 0.05g
Have everything in control and in order and discuss about different issues.