Answer:
Approximately 
(assuming that the projectile was launched at angle of 
above the horizon.)
Explanation:
Initial vertical component of velocity:
.
The question assumed that there is no drag on this projectile. Additionally, the altitude of this projectile just before landing 
is the same as the altitude 
at which this projectile was launched: 
.
Hence, the initial vertical velocity of this projectile would be the exact opposite of the vertical velocity of this projectile right before landing. Since the initial vertical velocity is 
(upwards,) the vertical velocity right before landing would be 
(downwards.) The change in vertical velocity is:
.
Since there is no drag on this projectile, the vertical acceleration of this projectile would be 
. In other words, 
.
Hence, the time it takes to achieve a (vertical) velocity change of 
would be:
.
Hence, this projectile would be in the air for approximately .
The answer would be:
The comb gains electrons.
The hair loses electrons.
In chemistry, the charge depends on the electrons and protons. The electron will give negative charge and proton will give the positive charge. Proton is located in the nucleus of the atoms so it won't easily move like electron which located in the orbit in the atoms perimeter. So, ignore the option with the proton.
If the combs become negatively charged, that means it gain some electron. Since something gain electron, that means another thing is losing an electron. That electron comes from the hair.
Is there a question in here somewhere?
Answer:
Explanation:
Remark
This is a momentum question. Both cars are sitting still (v1 and v2 are both 0) to start with). When the spring is sprung), they both move but in opposite directions.
Let us say that v4 is minus.
Equation
0 = m3*v3 - m4* v4
Givens
m3 = 1750 kg
m4 = 1000 kg
v3 = 4 m/s
Solution
m3*4m/s - m4*x = 0
1750 * 4 - 1000*x = 0
1750 * 4 = 1000x
7000 = 1000 x
7000/1000 = x
x = 7 m/s
Answer:
1) 10 m/s 2) 14.1 m/s 3) 6.7 m 4) 11.25 m 5) 4.5 m/s 6) 12 joules
Explanation:
