You have a 90 W electrical appliance that is on 24 hours per day. At $0.51 per kWh, how much are you paying daily for electricit
1 answer:
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Answer:
the final speed of object A changed by a factor of = 0.58
the final speed of object B changed by a factor of = 1.29
Explanation:
Given;
kinetic energy of object A, = 27 J
let the mass of object A =
then, the mass of object B =
work done on object A = -18 J
work done on object B = -18 J
let be the initial speed
let be the final speed
For object A;
Thus, the final speed of object A changed by a factor of = 0.58
To obtain the change in the final speed of object B, apply the following equations.
Thus, the final speed of object B changed by a factor of = 1.29
Answer:
The answer to the question is
The roller coaster will reach point B with a speed of 14.72 m/s
Explanation:
Considering both kinetic energy KE = 1/2×m×v² and potential energy PE = m×g×h
Where m = mass
g = acceleration due to gravity = 9.81 m/s²
h = starting height of the roller coaster
we have the given variables
h₁ = 36 m,
h₂ = 13 m,
h₃ = 30 m
v₁ = 1.00 m/s
Total energy at point 1 = 0.5·m·v₁² + m·g·h₁
= 0.5 m×1² + m×9.81×36
=353.66·m
Total energy at point 2 = 0.5·m·v₂² + m·g·h₂
= 0.5×m×v₂² + 9.81 × 13 × m = 0.5·m·v₂² + 127.53·m
The total energy at 1 and 2 are not equal due to the frictional force which must be considered
Total energy at point 2 = Total energy at point 1 + work done against friction
Friction work = F×d×cosθ = ( × mg)×60×cos 180 = -117.72m
0.5·m·v₂² + 127.53·m = 353.66·m -117.72m
0.5·m·v₂² = 108.41×m
v₂² = 216.82
v₂ = 14.72 m/s
The roller coaster will reach point B with a speed of 14.72 m/s