1. Newton’s second law can be written in mathematical form as ?F = ma. Within the summation of forces, ?F, ________ are (is) not included.
A) External forces
B) Weight
C) Internal forces
D) All of the above.
2. The equation of motion for a system of n-particles can be written as ?Fi = ? miai = maG, where aG indicates _______.
A) Summation of each particle’s acceleration
B) Acceleration of the center of mass of the system
C) Acceleration of the largest particle
D) None of the above.
3. In dynamics, the friction force acting on a moving object is always ________
A) In the direction of its motion.
B) A kinetic friction.
C) A static friction.
D) Zero.
4. If a particle is connected to a spring, the elastic spring force is expressed by F = ks . The “s” in this equation is the
A) Spring constant.
B) Un-deformed length of the spring.
C) Difference between deformed length and un-deformed length.
D) Deformed length of the spring.
5. The “normal” component of the equation of motion is written as ?Fn=man, where ?Fn is referred to as the _______.
A) Impulse
B) Centripetal force
C) Tangential force
D) Inertia force
6. The positive n direction of the normal and tangential coordinates is ____________.
A) Normal to the tangential component
B) Always directed toward the center of curvature
C) Normal to the bi-normal component
D) All of the above.
7. The normal force which the path exerts on a particle is always perpendicular to the _________
A) Radial line.
B) Transverse direction.
C) Tangent to the path.
D) None of the above.
8. When the forces acting on a particle are resolved into cylindrical components, friction forces always act in the __________ direction.
A) Radial
B) Tangential
C) Transverse
D) None of the above.