Answer:
The correct answer would be B. 18 to 26%.
The muscle efficiency is calculated by dividing mechanical work output by total metabolic cost.
It is estimated that human muscles have an efficiency of about 18% to 26%.
The efficiency is low because most of the energy is lost when food energy is converted into ATP (adenosine triphophate).
In addition, there is second energy loss when energy in the form of ATP is converted into the mechanical energy such as rowing, cycling et cetera.
I believe the answer is D. phase changes. The two level portions represents change of state that does not involve change in temperature (at a constant temperature). The first level represents a change of solid to liquid;p where the ice melts and becomes water by gaining the latent heat of fusion, while the other level represents a change of state from liquid to gas; the water changes to steam (water vapor) by gaining the latent heat of vaporization.
The magnitude of the force<span> a 1.5 x 10-3 C charge exerts on a 3.2 x 10-4 C charge located 1.5 m away is 1920 Newtons. The formula used to solve this problem is:
F = kq1q2/r^2
where:
F = Electric force, Newtons
k = Coulomb's constant, 9x10^9 Nm^2/C^2
q1 = point charge 1, C
q2 = point charge 2, C
r = distance between charges, meters
Using direct substitution, the force F is determined to be 1920 Newtons.</span>
This question is incomplete, the complete question is;
A weightlifter holds a 1,300 N barbell 1 meter above the ground. One end of a 2-meter-long chain hangs from the center of the barbell. The chain has a total weight of 400 N. How much work (in J) is required to lift the barbell to a height of 2 m?
What is the average force (average with respect to height of the barbell from the ground) exerted by the weightlifter in the process?
Answer: Average force exerted by the weightlifter in the process = 1600N
Explanation:
To find Work done to lift a barbell and half of the hanging chain we say;
W₁ = ( 1300N + (1/2 × 400N)) × 1m
W₁ = (1300 + 200) Nm
W₁ = 1500J
now work done to lift the upper half of the chain we say:
W₂ = (1/2 × 400N) × (1/2 × 1m)
W₂ = 200N × 0.5m
W₂ = 100J
So total work done will be
W = W₁ + W₂
W = 1500J + 100J
W = 1600J
To find the average force exerted by the weight lifter, we say;
F = W/D
F = (1600 / 1m) N
F = 1600N
∴Average force = 1600N
Answer:
The resistance is 
Explanation:
From the question we are told that
The voltage rating of the headlamp is 
The voltage of the power system is 
The power rating of the headlamp is 
Generally the power which the resistor dissipates is mathematically represented as
=> 
=> 
Generally the resistance is
