Answer:
86.4 m horizontal from landing spot
Explanation:
Find out how long before the ball hits the ground
vertical speed of ball = -2 m/s gravity = - 9.81 m/s^2
find time to hit ground from 100 m
( height will be<u> zero</u> when it hits the ground)
<u>0 </u>= 100 - 2 t - 1/2 ( 9.81) t^2
use Quadratic Formula to find t = 4.32 seconds
horizontal speed of ball = 20 m/s
in 4.32 seconds it will travel horizontally 20 m/s * 4.32 s = 86.4 m
Answer:
0.0321 g
Explanation:
Let helium specific heat 
Assuming no energy is lost in the process, by the law of energy conservation we can state that the 20J work done is from the heat transfer to heat it up from 273K to 393K, which is a difference of ΔT = 393 - 273 = 120 K. We have the following heat transfer equation:
where 
is the mass of helium, which we are looking for:
True that is what a convection current is
Answer:
Explanation:
For calculating resistance of a conductor , the formula is
R = ρ l / A , ρ is specific resistance , l is length and A is cross sectional area of wire.
For first wire length is l₁ , area is A₁ resistance is R₁, for second resistance is R₂ , length is l₂ and area is A₂
Given , l₁ = 2l₂ , A₁ = 4A₂ , area is proportional to square of thickness.
R₁ / R₂ = I₁A₂ / I₂A₁
= 2l₂ x A₁ / 4 I₂A₁
= 1 / 2
2R₁ = R₂
Power = V² / R
Ratio of power = (V² / R₁) x (R₂ / V²)
= R₂ / R₁
= 2 .
