A plastic sample 4.0 inches long (distance between the grips in a tensile test apparatus), 2.0 inches wide, and 0.007 inch thick is subjected to stress-strain measurement.

At an elongation of 0.25 inch, the measured force is 35 lbs.

At an elongation of 0.50 inches, the measured force is 48 lbs.

At an elongation of 0.75 inches, the measured force is 57 lbs.

At an elongation of 1.00 inches, the measured force is 63 lbs.

At an elongation of 1.25 inches, the measured force is 49 lbs.

The force-deflection curve is linear up to 0.25 inch elongation.

The material breaks at 1.25 inches of elongation.

Determine the following, based on the information above, and show your calculations.

a. Tensile strength. (2 points)

b. Tensile modulus. (2 points)

c. Stress at yield. (2 points)

d. Break stress. (2 points)