Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion.
Answer:
Explanation:
Different measuring instruments have different level of precision . For example , our usual scale can measure upto 1 mm. Callipers can measure upto .1 mm. screw gauge can measure upto .01 mm.etc The deeper it can measure , the more precise it is. Hence screw gauge is most precise among the three.
On this basis we can say that , new caliper is less precise than old one.
Accuracy tells us about our result , how close our result is to the true measurement. It is dependent on the manner in which we take reading , So measuring methods , rather than measuring instruments , decide the accuracy of our result.
Hence we can say that the new caliper is less precise only.
Answer:
The archerfish must spit at a minimum speed of 
at an angle of 
above the horizontal.
Explanation:
Hi
First of all, we need to find the angle above the horizontal at which the archerfish must spit, as we can see in the attachment this angle is 
.
Then we use the formula 
, as we clear it for 
, we obtain, 
, therefore the archerfish must spit at a minimum speed of at an angle of above the horizontal.
