Exam 1 TB Flashcards
The study of the time and space characteristics of movement is called?
Kinematics
The study of systems with no change in their state of motion is called?
Statics
The study of the force and energy factors associated with systems in motion is called?
Kinetics
Kinematics is the branch of mechanics that?
Describes the pattern of motion.
Which of the following could not be involved in a kinematic description of a tennis serve?
a. angular velocity
b. linear velocity
c. force
d. angular acceleration
e. all of the above
c. force
The primary focus of sport and exercise biomechanics is to?
Improve performance and reduce the risk of injury.
Interia is
A body’s resistance to having its state of motion changed.
Mass is an important quantity in kinetics because it quantifies
a. the rate of change of motion of a body
b. the quality of matter in a body
c. the net force acting on a body
d. the inertia of a body
e. none of the above
The inertia of the body
The process of taking all of the independent forces acting on an object and calculating the net force is termed?
Force composition or force resolution?
Force resolution.
A free body diagram displays
the forces acting on a body
If two forces lying in the same plane are added together and the result is zero, which of the following is true of the forces?
a. They are in opposite directions
b. They are equal in magnitude
c. Both a and b are true
d. None
c. Both a and b are true
The forces that acts perpendicular to an object in contact with a surface is called?
Normal force
The force that acts parallel to an object in contact with a surface is called?
Friction force
As the normal contact force increases, what happens to the friction force?
It increases
If a normal force of 500N is acting on two surfaces in contact with a coefficient of friction equal to 0.50, what would be the maximum force of static friction.
250N
As the surface area of two objects in contact increases (for instance laying a refrigerator on its side), what happens to the force of friction?
It remains constant.
How does mass differ from weight?
Weight is force and mass is the quantity of matter in a body.
Which objective is always desirable in human movement?
The amount of friction desired varies with the particular situation within a given activity.
To fully define a vector quantity, you must specify
A direction and a magnitude
Which of the following statements is true of the amount of horizontal force required to start in motion an object sitting on a horizontal surface?
It must be greater than the maximum static friction FORCE.
Which type of motion describes the flight of a softball after it leaves the bat and sails in an arc over the outfield fence?
Curvilinear motion.
A softball is fouled off with a vertical velocity of 20m/s and a horizontal velocity of 15 m/s. What is the resultant velocity of the ball?
25m/s
A2 + B2 = C2
What of the following terms best describes linear motion along a curved line?
Curvilinear
When a runner has completed one full lap around a 400m track, what is the runners distance with respect to the starting position?
400m
Which category of motion encompasses most human movement?
General motion
What factor differentiates velocity from speed?
direction
Acceleration described the time rate of change of
velocity
In mechanics, acceleration may be used to describe
a. a change in motion at rest or in motion
b. an increase in speed of a body at rest
c. a change in direction of a moving body
d. all of the above
e. none of above.
d. all of the above
Newton’s first law focuses on
Inertia
Which of Newton’s laws is described by the equation F = ma?
Second Law
An unbelted victim in a car accident will continue to move in the same direction an with the same speed until the dashboard causes a change in motion. This best exemplifies
Newton’s first law of motion.
If a body of constant mass if traveling with a constant velocity
There must be NO NET FORCE acting on the body
According to Newton’s third law, then two bodies collide
The FORCE applied to each body will be the SAME size
A 500N gymnast performs a stationary handstand on the high bar. How much force is exerted by the bar on the gymnast’s hands?
500N
The product of a force and time during which the force acts on the body defines
Linear IMPULSE
If you increase the time during which a constant force is applied to an object, what effect does this have on the impulse given to the object?
It increases the impulse.
If an athlete moves faster, what happens to her momentum?
It increases.
An example of using impulse to safely decrease momentum would be
landing on a mat when pole vaulting.
The principle of conservation of momentum restates
Newton’s first law
Power is equal to
Force times displacement divided by time.
Where force x displacement is work.
Power is defined as
the rate of doing work
The form of energy associated with the stiffness and deformability of an object is called?
Strain energy
In the kinetic energy equation, which component is most important?
Velocity
In the equation for calculating strain energy, the x symbolizes
The amount of dormation
A person performs a bench press. The bar’s mass is 50kg. When this person’s arms are extended, the bar is 0.6m above the starting point. How much work did the person do to push the bar off his chest to pull extension?
W = F x d
F = ma
300N
Strain energy is the nergy
due to deformation
During an arm wrestling match, your opponent is winning. She is slowly pushing your warm down toward the table. Are you doing any mechanical work agist your opponent?
Yes
During an arm wrestling match, your opponent is winning. She is slowly pushing your arm down toward the table. If you are doing any mechanical work against your opponent, the work is…?
Negative work
The capacity for doing work that a body possesses because of its position or configuration is known as?
Potential energy
If the velocity of a runner changes from -2 m/s to -4 m/s over a period of time, the runners kinetic energy will become
Four times as great
Use KE = 1/2mv2
