Modterm Flashcards
How do you best represent a vector mathematically?
Magnitude and direction (length gives you the magnitude and the direction shows you the angle)
What is materials science?
Study of stress and strain relationships and shear also looks at chemistry and physics
You take two vectors and both in the same direction how do you add them together?
You just add them
A another way of representing a vector on a graph is using X and Y coordinates what is it called?
Rectangular coordinates
If you throw a ball up at an angle whatever degrees what is the vertical coordinate equal to?
Gravity- vertical coordinate
Horizontal velocity - horizontal velocity
What is Newton’s first law?
“An object at rest tends to stay at rest and object in motion will tend to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.”
What is Newton’s 2nd law?
F= MA: acceleration = force/mass; force causes acceleration
What is Newtons 3rd law?
“Every action has an equal and opposite reaction”
Define inertia?
The resistance an object has to a change in its state in motion
True or false inertia is massly proportional to mass?
True
If you are in a car and slamming on the brakes applies which newtons law?
Newtons 1st law an object in motion will stay in motion
What is the static coefficient of friction?
The force that holds back a stationary object up to the point that it just starts moving
What is potential energy?
Stored energy
What is kinetic energy?
Mass in motion KE= 1/2mv^2 or the energy of motion
What’s the formula for momentum?
P= M*V Momentum = mass x velocity ; a force acting upon an object to cause a displacement
Is work a unit of power?
The amount of work you do per unit time is called power; displacement
Power = work/time
Power = force *velocity
Define torque?
Force times distance turning something into a circle rotational motion; it is a measure of how much a force acting on an object causes that object to rotate
Where does the center of gravity falls for a women or men?
For women is through the hips
For men 2” higher
W
Decriibe a first class lever?
The fulcrum is between the load and effort
Examples (scissors, pliers, seesaw)
Describe a 2nd class lever?
Fulcrum and effort at opposite ends and the load is somewhere between the two (wheelbarrow)
Describe a 3rd class lever?
The fulcrum is at the end whereas the effort is in the middle
Examples: biceps
The head is what order lever?
First order lever
Standing on the toes is what type of lever?
2nd class lever
What is limits of stability?
Balance platform if center of gravity fall from center of hip to the silhouette of the foot
It is stable if it falls on the outside
The base is unstable
Compression fx is most common in persons with wheelchair at the ?
Head of the femur
Define plasticity?
Bends and stays bend but doesn’t break
Define elasticity?
An object bends but return to its original shape
If you are on a table in you jump down what keeps you from tearing the muscles in your lower leg?
Tendons they Are elastic like a rubber band or a spring
What causes a spiral fracture?
Twisting and rotation
What elastic material is under a tendon that protects the tendon?
Hyaline cartilage from touching the bone during motion
Are disc elastic?
Yes
When building an orthotic device across the knee where should the orthotic device be in relation to the knee?
Right over the center of rotation at the knee
Where is the fracture point?
At the end of the plastic region
Is bone very pLastic?
No it’s elastic
Is a muscle a linear or non linear force generator?
Non linear
Which develop more coarse the long arrangement of fibers or the pinnate arrangements?
Pinnate muscles are stronger
