Dddddddddddddddddddddddddddddddddddddddddddddddddddddd
Answer:
The answer to your question is given below.
Explanation:
Mechanical advantage (MA) = Load (L)/Effort (E)
MA = L/E
Velocity ratio (VR) = Distance moved by load (l) / Distance moved by effort (e)
VR = l/e
Efficiency = work done by machine (Wd) /work put into the machine (Wp) x 100
Efficiency = Wd/Wp x100
Recall:
Work = Force x distance
Therefore,
Work done by machine (wd) = load (L) x distance (l)
Wd = L x l
Work put into the machine (Wp) = effort (E) x distance (e)
Wp = E x e
Note: the load and effort are measured in Newton (N), while the distance is measured in metre (m)
Efficiency = Wd/Wp x100
Efficiency = (L x l) / (E x e) x 100
Rearrange
Efficiency = L/E ÷ l/e x 100
But:
MA = L/E
VR = l/e
Therefore,
Efficiency = L/E ÷ l/e x 100
Efficiency = MA ÷ VR x 100
Efficiency = MA / VR x 100
Answer:
<em>Its speed will be 280 m/s</em>
Explanation:
<u>Constant Acceleration Motion</u>
It's a type of motion in which the speed of an object changes by an equal amount in every equal period of time.
If a is the constant acceleration, vo the initial speed, vf the final speed, and t the time, vf can be calculated as:
The object accelerates from rest (vo=0) at a constant acceleration of 
. The final speed at t=35 seconds is:
Its speed will be 280 m/s
Answer:
Gwen’s assumption of asteroid hit as long term change is incorrect. Asteroid hit is not a long term change, instead, it is a short term change.
Explanation:
Examples of short term changes are drought, flood, volcanic eruption, etc. A short term change occurs quickly and can immediately affect organisms but it doesn’t become a reason for species extinction. The effects of a short term change don’t prevail over a long span of time.
Examples of long term changes are ice age, global warming, deforestation, etc. Unlike a short term change, it takes time but the consequences are far-reaching. It can lead to species extinction.
In this question, asteroid hit is a quick and unexpected hazard, unlike the slow long term environmental changes.
Answer:
Approximately 
(rounded down,) assuming that 
.
The number of repetitions would increase if efficiency increases.
Explanation:
Ensure that all quantities involved are in standard units:
Energy from the cookie (should be in joules, 
):
.
Height of the weight (should be in meters, 
):
.
Energy required to lift the weight by 
without acceleration:
.
At an efficiency of 
, the actual amount of energy required to raise this weight to that height would be:
.
Divide 
by 
to find the number of times this weight could be lifted up within that energy budget:
.
Increasing the efficiency (the denominator) would reduce the amount of energy input required to achieve the same amount of useful work. Thus, the same energy budget would allow this weight to be lifted up for more times.
