It’s assumed that a graphite-epoxy reinforced plastic with longitudinal fibers contains 25% graphite fibers (i. e. volume or area fraction). the elastic modulus of the fibers is 400gpa, and that of the epoxy matrix is 150 gpa. (a) calculate the elastic modulus of the composite and fraction of the load supported by the fibers. (b) calculate also the stresses in the fibers and in the matrix if the cross-sectional area and load of the composite are ac = 0.3 in2 and pc = 600 lb.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2