Try B, it seems correct. I’m very sorry if i’m incorrect.
Answer:
Some work input is lost to friction
Explanation:
The efficiency of a machine is defined as:
(1)
where
is the work output
is the work input
Due to the law of conservation of energy, the work output can never be larger than the work input (because energy cannot be created). Moreover, in real machines part of the work input is lost due to the presence of frictions: as a result, part of the energy in input is converted into thermal energy or other forms of energy, and so the work output is smaller than the work input, and so the ratio (1) becomes less than 1, and so the efficiency is less than 100%.
Answer:
The force bumper at 0.200m
F=2722.5 N
Explanation:
Using the energy theorem of work

W=ΔK
W=F*d
ΔK=

ΔK=F*d=

Answer:
The time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds.
Explanation:
Given that,
Acceleration of the car, 
Initial speed of the car, u = 24.6 m/s
Final speed of the car, v = 26.8 m/s
We need to find the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s. The acceleration of an object is given by :


t = 0.84 seconds
So, the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds. Hence, this is the required solution.
Answer:
laser light source
Explanation:
A laser light source provides substantially more brightness than a xenon bulb, and allows IMAX to power its largest screens with even sharper and more lifelike images.