Certain neutron stars (extremely dense stars) are believed to be rotating at about 500 rev/s. If such a star has a radius of 17
1 answer:
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Answer:
Approximately (assuming that the projectile was launched at angle of
above the horizon.)
Explanation:
Initial vertical component of velocity:
.
The question assumed that there is no drag on this projectile. Additionally, the altitude of this projectile just before landing is the same as the altitude
at which this projectile was launched:
.
Hence, the initial vertical velocity of this projectile would be the exact opposite of the vertical velocity of this projectile right before landing. Since the initial vertical velocity is (upwards,) the vertical velocity right before landing would be
(downwards.) The change in vertical velocity is:
.
Since there is no drag on this projectile, the vertical acceleration of this projectile would be . In other words,
.
Hence, the time it takes to achieve a (vertical) velocity change of would be:
.
Hence, this projectile would be in the air for approximately .
(a) 23.4
The fiber-to-matrix load ratio is given by
where
is the fiber elasticity module
is the matrix elasticity module
is the fraction of volume of the fiber
is the fraction of volume of the matrix
Substituting,
(1)
(b) 44,594 N
The longitudinal load is
F = 46500 N
And it is sum of the loads carried by the fiber phase and the matrix phase:
(2)
We can rewrite (1) as
And inserting this into (2):
Solving the equation, we find the actual load carried by the fiber phase:
(c) 1,906 N
Since we know that the longitudinal load is the sum of the loads carried by the fiber phase and the matrix phase:
(2)
Using
F = 46500 N
We can immediately find the actual load carried by the matrix phase:
(d) 437 MPa
The cross-sectional area of the fiber phase is
where
is the total cross-sectional area
Substituting , we have
And the magnitude of the stress on the fiber phase is
(e) 8.0 MPa
The cross-sectional area of the matrix phase is
where
is the total cross-sectional area
Substituting , we have
And the magnitude of the stress on the matrix phase is
(f)
The longitudinal modulus of elasticity is
While the total stress experienced by the composite is
So, the strain experienced by the composite is