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SUDESHNA PAUL
EDUCATIONAL COMPANION

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Physics

**A Car moving at uniform velocity,
is suddenly brought to rest ,by application of brakes. Its velocity falls to
zero instantly and so its kinetic energy .**

# when the car is in uniform velocity

Equation
: **(1/2)mv**^{2
}= f_{k}d_{1}

** when
the car brakes are applied**

**Equation
: Fd=
(1/2)mv**^{2} – (1/2)mv^{2}_{f } +
f_{k}d

** F
= **force applied by the brakes**
**

f_{k
}= frictional force of
the ground

m
= mass of the ground

d_{1}=
distance covered by the car before brakes are applied

d
= distance covered by the car after brakes are applied

v
= uniform velocity of the car

v_{f
}= final velocity after retardation by brakes (since the car comes
to rest v_{f }=0)

Energy Conservation on an
Incline

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As the ball rolls down the hill from its
elevated position, its mechanical energy is transformed from potential energy to
kinetic energy. At a height just above the ground, the majority of energy is in
the form of kinetic energy. This is to say, energy due to vertical position has
been transformed into energy due to motion

Work on Inclined Plane

Three different incline
angles could be used to represent the three different paths up the mountain The
amount of work done to raise the cart from the floor to the seat top is
dependent upon the force applied to the cart and the displacement caused by this
force

The amount of work done by a force on any object is given by
the equation

Work = F * d * cosine(Theta)
where F is the force, d is the
displacement and Theta is the angle between the force and the displacement
vector. The least steep incline (30-degree incline angle) will require the least
amount of force while the most steep incline will require the greatest amount of
force. Yet, force is __not__ the only variable affecting the amount of work
done Another variable is the displacement .the least steep incline would
correspond to the largest displacement and the most steep incline would
correspond to the smallest displacement. The final variable is Theta - the angle
between the force and the displacement vector

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