4. What is energy efficiency, and why is increasing it important?
1 answer:
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Answer:
The instantaneous velocity of the rocket the moment before it hits the ground is 50 m/s.
Explanation:
Given;
initial velocity of the rocket, u = 50 m/s
Determine the maximum height reached by the rocket.
at maximum height reached by the rocket, the final velocity, v = 0
v² = u² -2gh
0 = 50² - 2(9.8)h
19.6h = 2500
h = 2500 / 19.6
h = 127.55 m
At maximum height, the time to reach ground is given by;
h = ¹/₂gt²
Before the rocket hits the ground the final velocity will be maximum;
v = u + gt
v = 0 + 9.8 x 5.1
v = 50 m/s
Therefore, the instantaneous velocity of the rocket the moment before it hits the ground is 50 m/s.
Answer:
Explained
Explanation:
Resistance R in a current flow through an object is given by
ρ = resistivity of the material
L= length of the object
A= area of cross section
clearly resistance is directly dependent on length of the object.This means greater the length larger will be resistance to current.
thermal resistance R_th is given by
L= length of the object
A= area of cross section
K = Conductivity of the material
thermal resistance is also is directly dependent on length of the object.This means greater the length larger will be resistance to current.