Forces on Materials

........ applied on a body can cause a change in either the shape or the motion of the body. This statement refers to

• Load

• Area

• Force

• Material

The unit of force is Newton.

• True

• False

These are type of load,except..

• Static

• dynamic

• impact

• motion

A rectangular bar having a cross sectional area of 70m2 and force 30kN applied to it. Find stress.

• 2100 N

• 428.57 kN/m²

• 428.57 N/m²

• 2.333x10^-3 N/m²

Effects of load are..

• Elongation

• Shortening

• Crash

• Bending

Strain formula is...

•  $\epsilon=\frac{\Delta L}{L}$  

•  $\epsilon=\frac{L}{\Delta L}$  

•  $\epsilon=\frac{F}{A}$  

•  $E=\frac{\sigma}{\epsilon}$  

A bar 1.5m long contracts axially by 0.11mm when compressive load is applied. Determine strain.

• 7.33x10^-5

• 7.33x10^-5 m

• 0.0733

• 0.0733m

Squeezing a lemon

• Tension force

• Compression force

• Shear force

Cut the paper with scissors

• Shear force

• Dynamic force

• tension force

Hammer knocks on nail

• Static load

• dynamic load

• Impact load

• Fatigue load