Write down the principal of lever
1 answer:
Answer:
See the explanation below.
Explanation:
A lever is a simple machine that changes the magnitude and direction of the force applied to move an object. Minimizes the force needed to lift the object.
By means of the following image, we can see the principle of operation of a lever.
The load can be moved thanks to the force multiplied by the distance to the fulcrum.
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Answer:
A) Increases by a factor of 2
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Given that mass, m = 2m
Substituting into the equation, we have;
K.E = ½mv²
K.E = ½*2mv²
Cross-multiplying, we have;
2K.E = 2mv²
Hence, if the mass of an object increases by a factor 2, kinetic energy is increased by a factor of 2.
1) Maximum
2) Maximum
Explanation:
The force acting on a mass on a spring is given by Hooke's law; in magnitude:
where
F is the force
k is the spring constant
x is the displacement
Also we know from Newton's second law that we can write
where
m is the mass
a is the acceleration
So we can write the equation as
(1)
From this relationship, we see that the acceleration is directly proportional to the displacement.
On the other hand, we know that the total mechanical energy of the system mass-spring is constant, and it is given by
(2)
where the first term is the elastic potential energy while the second term is the kinetic energy, and where
v is the velocity of the mass
From eq. (2), it is clear that when displacement increases, velocity decreases, and vice-versa; however, from eq.(1) we also know that acceleration is proportional to the displacement.
Therefore this means that:
- When acceleration increases, velocity decreases
- When acceleration decreases, velocity increases
Therefore, the two answers here are:
- When the acceleration of a mass on a spring is zero, the velocity is at a maximum
When the velocity of a mass on a spring is zero, the acceleration is at a maximum