Answer:
0.25223 seconds.
Explanation:
= Mass of bullet = 0.0146 kg
= Mass of block = 2.55 kg
v = Combined velocity
= Velocity of bullet = 816 m/s
g = Acceleration due to gravity = 9.81 m/s²
As linear momentum is conserved
Now 
as the block (with the bullet in it) reverses direction and rises,
Equation of motion
The time t is 0.25223 seconds.
Answer:
if a gas produced, most likely a chemical reaction took place
Explanation:
Number one a and b are automatically out if you decrease the pitch or frequency you wont hear it louder it does not add up ok?
number 2 the answer would be C the higher the frequency the higher the pitch the lower the frequency the lower the pitch this just comes back to common sense. for example you cant decrease the frequency and than expect a louder pitch its like saying I am going to smash the key on this piano with all my strength and it will make a small very low pitch sound you get what I mean so your answer would indeed be C.
C. Combustion reaction.
These reaction are exothermic.
The reactions are:
2Mg + O2 -----> 2MgO
3Mg + N2 ------> Mg3N2
Answer:
The molecules in hot air are moving faster than the molecules in cold air.
