Answer:
Hey
Say that there was no light on in the building that they were ch,at,tin,g in, then they could hear each other but not see each other.
Answer:
a) The answer is 11,7m
b) The time it takes to fall will be shorter
Explanation:
We will use the next semi-parabolic movement equations
Where g(gravity acceleration)=9,81m/s^2
Also Xi, Hi and Viy are zero, as the stones Billy-Jones is kicking stay still before he moves them, so we take that point as the reference point
The first we must do is to find how much time the stones take to fall, this way:
Then t=1,54s
After that we need to replace t to find H, this way
Then H=11,7m
b) The stones will fall faster as the stones will be kicked harder, it will cause the stones move faster, it means, more horizontal velocity. In order to see it better we could assume the actual velocity is two times more than it is, so it will give us half of the time, this way:
Then, t=0,77
The answer to question one is A.
The answer to question two is A.
The answer to question three is D.
A positive charge cause dosent your hair static up when that happens or no?
Answer:
α = 2,857 10⁻⁵ ºC⁻¹
Explanation:
The thermal expansion of materials is described by the expression
ΔL = α Lo ΔT
α = 
in the case of the bar the expansion is
ΔL = L_f - L₀
ΔL= 1.002 -1
ΔL = 0.002 m
the temperature variation is
ΔT = 100 - 30
ΔT = 70º C
we calculate
α = 0.002 / 1 70
α = 2,857 10⁻⁵ ºC⁻¹