Answer:
The kinetic energy of the wagon is 967.0 J
Explanation:
Given that,
Force = 120 N
Mass = 55 kg
Height = 8 m
We need to calculate the kinetic energy of the wagon
Using newtons law
Using equation of motion
Where,
v = final velocity
u = initial velocity
s = height
Put the value in the equation
Now, The kinetic energy is
Hence, The kinetic energy of the wagon is 967.0 J
Answer:
K'=4K
Explanation:
The electric potential energy is given by :
Where
k is spring constant
x is compression or extension in the spring
If the displacement of a horizontal mass-spring system is doubled, x'= 2x
New elastic potential energy :
So, new elastic potential energy 4 times the initial elastic potential energy.
The speed of a electron that is accelerated from rest through an electric potential difference of 120 V is
We know, that the energy of the system is always conserved.
Using the Law of Conservation of energy,
U=0
Here, K is the kinetic energy and U is the potential energy.
Now, substituting the formula of U and K, we get:
=0------(1)
Here,
m is the mass of the electron
v is the speed of the electron
q is the charge on the electron
V is the potential difference
Let and
represent the final and initial speed.
Here, =0
Solving for , we get:
=6.49m/s
To learn more about the conservation of energy, refer to:
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