Answer:
maximum force (in N) can you exert horizontally on the crate without moving it = 564.075 N
Explanation:
Given data:
mass m= 115 kg
coefficient of friction μ =0.5
according to newton law of motion the net force acted on body is given by

here the body is in rest ,

N= it is the normal reaction force
N= mg = 115×9.81
therefore,

Explanation:
Total Internal Reflection (TIR) is a phenomenon in optics, by which light experiences complete reflection at an interface between two media.
In the figure i > © experience total internal reflection
Explanation:
Echoes occur due to the reflection of sound from any obstacle, but not all the reflected sound waves lead to the phenomenon of echo. For the echo to be heard it actually depends upon the human perception as well, human ears can encounter the difference between the sound wave directly form the source and the reflected sound waves only if there is a minimum time gap of one-tenth of a second. For this time gap in the atmosphere at normal temperature and pressure the obstacle must be at least 7 meters away from the sound source.
Answer:
10
Explanation:
This is tough. The last number 0.2 has only one significant figure. So while the sum of all the numbers is 12.3, you must only leave one sig figure. Rounding to the tenths gives 10.