What would happen to a moving object if no unbalanced force acts upon it? Help please?
1 answer:
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The question is incomplete. The complete question is :
Consider a composite cube made of epoxy with fibers aligned along one axis of the cube (the fibers are parallel to four of the twelve cube edges). If the cube can only be loaded in axial tension such that the force is uniformly applied over - and is normal to - a cube face, what is the lowest possible positive length change the cube can experience under this tension? The applied tensile force is 102 KN. The unloaded cube edge length is 56 mm. The glass fibers have an elastic modulus of 200 GPa. The epoxy has an elastic modulus of 38 GPa. The cube is comprised of 18 vol% epoxy (the balancing vol % is glass fiber). Hint: The loading axis is intentionally unspecified. Answer Format: Lowest possible length increase (change of length) under tension.
Solution :
Given :
= 200 GPa
= 38 GPa
Edge length = 56 mm
Cube is loaded in axial tension such that the force is uniformly applied over a cube face.
GPa
Applied stress
= 32.5 MPa
By Hooke's law
Length change,
= 0.016 mm
Answer: Option (b) is the correct answer.
Explanation:
The given data is as follows.
= 30 J, l = 10 cm = 0.1 m (as 1 m = 100 cm)
F = 10 N
The formula to calculate the work done is as follows.
W =
Hence, putting the given values into the above formula as follows.
W =
=
= 1 J
As the dart loses 1 joule of energy when it goes through the barrel. Therefore, the kinetic energy it has when it comes out is calculated as follows.
K.E = 30 - 1
= 29 J
Thus, we can conclude that the kinetic energy of the fired dart is 29 J.