<h3><u>Answer;</u></h3>
= 75 %
<h3><u>Explanation</u>;</h3>
To measure efficiency of a machine, compare the work output to work input.
Efficiency = Work output/ work output × 100 %
= 300/400 × 100
= 75 %
Complete Question
The complete question is shown on the first uploaded image
Answer:
the change in energy of the block due to friction is
Explanation:
From the question we are told that
The frictional force is
The mass of the block is
The length of the ramp is
The height of the block is
The change in energy of the block due to friction is mathematically represented as
The negative sign is to show that the frictional force is acting against the direction of the block movement
Now substituting values
The beginning of the universe is from the big bang which is a massive explosion.
The Big Bang is the moment when the universe began 13.8 billion years ago with the explosion of a small, dense fireball. However, what caused the explosion in the first place remains a mystery.
A Big Bang event is a physical theory that explains how the universe expands from a dense and hot initial state. Various cosmological models of the Big Bang explain the evolution of the observable universe from the earliest known epochs to later large-scale forms.
In 1929, Edwin Hubble provided the first observational evidence that the age of the universe is finite. Using the largest telescope of its time, he discovered that the farther away a galaxy is from us, the more it appears that the space is expanding from us in all directions.
Learn more about the big bang in
brainly.com/question/17209127
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The car travels at a speed of 25m/s.
<u>Explanation:</u>
Given-
Mass, m = 1500kg
Coefficient of friction, μk = 0.47
Distance, x = 68m
Speed, s = ?
We know,
and
F = μ X m X g
Therefore,
μ * m * g = m * a
μ * g = a
Let, g = 9.8m/s²
So,
We know,
where, v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
If the car comes to rest, the final velocity, v becomes 0.
So,
The car travels at a speed of 25m/s.
Answer: x = 0.957 m
Explanation:
F = ma
d = ½at²
a = 2d/t²
F = m2d/t²
F = kx
kx = m2d/t²
x = 2md/kt²
x = 2(8.86)(4.36) / (471(0.414²))
x = 0.957036...