Impulse Momentum Theorem Flashcards
How is momentum different from inertia?
Momentum is a vector while inertia is a scalar. Inertia is how much something resists motion while momentum is how much motion an object has.
How is change in momentum related to impulse?
Change in momentum is equal to impulse.
What are the conditions to achieve change in momentum?
Mass and velocity need to be increased or decreased.
Which do you think is harder to stop, motorcycle or truck?
Truck, because it has more mass, considering that they are moving in the same speed.
Why do you bend your knees when returning from a jump?
To prolong the time which lessens impact, hence lessening impulse to body. More time = less force.
What are Newton’s 3 laws of motion?
Law of inertia, acceleration, and interaction.
Definition of momentum? Formula? Unit?
Mass in motion.
P= mv
kgm/s
Is momentum a vector quantity? How?
Yes because mass is a scalar while velocity is a vector.
Define the law of inertia?
It is the natural tendency of an object to resist motion.
When is momentum negative?
When velocity direction is to the left.
When is momentum 0?
When an object is at rest.
What is the relationship between inertia and momentum?
Greater inertia = more momentum.
Define the law of acceleration? Its formula?
An unbalanced force can speed up or speed down an object. F= ma
How is Newton’s 2nd law related to momentum?
Unbalanced force = change in momentum.
Definition of impulse? Formula? Unit?
States that force and time are inversely proportional.
I= Ft
Ns
What can unbalanced forces cause and what does it change?
Unbalanced forces cause an object to speed up or speed down and it changes an object’s momentum.
Describe the impulse-momentum theorem?
Change in momentum = impulse.
Define the law of interaction?
Every action has its equal opposite reaction.
How is Newton’s third law related to collision?
Momentum before the collision is equal to momentum after the collision. Proves that every action has its equal opposite reaction.
Describe the law of conservation of momentum?
The total momentum of 2 or more objects remains constant unless an unbalanced force acts upon them.
What are the 3 units for energy?
J, Nm, kgm^2/s^2
Define energy?
The ability or capacity of something to do work.
Where is chemical energy from?
Chemical reactions.
Where is heat energy from?
Thermal processes.
Where is electrical energy from?
Charged particles.
Where is nuclear energy from?
Fusion of atoms.
Where is kinetic energy from?
Motion.
Where is potential energy from?
Position.
Where is mechanical energy from?
Position and Motion.
What is mechanical energy?
Energy transferred when work is done, and the sum of potential and kinetic energy.
What are the 2 forms of mechanical energy?
Potential and kinetic energy.
What is potential energy?
Stored energy that allows an object to do work and energy possessed due to position.
What are the 2 types of potential energy?
GPE and EPE.
Describe GPE? Formula?
Energy an object has due to its height.
mgh
Describe EPE? Formula?
Energy an object has due to stretching or compressing.
kx^2/2
What is kinetic energy? Formula?
Energy possessed due to motion. Depends on velocity.
mv^2/2
Describe the conservation of mechanical energy?
Mechanical energy is always equal to the sum of kinetic and mechanical energies. The change in mechanical energy is 0 because no energy is created not destroyed but transferred.
What are the 3 ways of heat transfer?
Conduction, convection, and radiation.
How is heat transfer done?
From a region of hot to cold.
Differentiate conduction, convection, and radiation?
Conduction: solid, contact
Convection: liquids or gases, density
Radiation: no object needed, waves
What is the symbol for heat?
Q
Define heat?
Another form of energy related to work.
Do work and energy have the same unit? What are they?
Yes. J, Nm, kgm^2/s^2
Define work? Formula? Unit?
Transfer of energy when force is applied through a distance.
W= Fd
J, Nm, kgm^2/s^2
Give examples of not doing work?
Laying down or listening to a zoom class without moving
What is the work-energy theorem?
When work is done, there is change in energy.
What is Newtons equal to?
kgm/s^2
When is work negative?
When speed of object decreases.
Define power? Formula? Units?
Rate at which energy is transformed or work done in a certain period of time.
P= W/t
Watts or J/s
What is mechanical work?
Amount of energy transferred due to work.
Define the first law of thermodynamics?
States that when heat is added, the system does external work and its internal energy increases.
Define the second law of thermodynamics?
States that once heat goes out the system with cold system, it cannot go back to its original state.
Differentiate the main difference between heat pumps and heat engines?
Heat pumps flow from cold to hot while heat engines flow from hot to cold.
Define efficiency?
Efficiency is the quality of work done by an engine to an object.
What are the 2 formulas for efficiency and when are they used?
(Thot-Tcold)/Thot x 100% (KELVIN)
Qout/Qit) x 100% (JOULES
How do you determine which number will be used for hot and cold when computing for efficiency?
The higher number will be designated for the hot air.
How do you convert Celcius to Kelvin?
Add 273 to Celcius.
Why is 100% efficiency not possible?
Because some of the air goes to the exhaust.
What does low efficiency imply?
It means that more energy is used, hence a bigger bill is asked.
How is an EEG useful?
Shows us the voltage capacity of an appliance, and we can use this to match it up with the capacity of our house’s voltage.
Why are women more stable than men?
Women’s COMs are on the pelvic area while men’s are on the upper abdomen area.
Why do old people need a cane for them to balance?
As people age, their posture changes, hence their COM adjusts.
What method can we use to determine COM?
Plumbline method.
What are the 3 types of equilibrium?
Stable, Unstable, and neutral equilibrium.
Define stable equilibrium?
The object will have minimal to no movement when a force is applied. An example is an upright cone.
Define unstable equilibrium?
The object will topple over when a force is applied. An example is an inverted cone.
Define neutral equilibrium?
The object will roll over and change its position when a force is applied. An example is a cone on its side.
Define base support?
Is the area within an object in contact with the ground.
How can we maintain balance when we stand up for a long time?
We need to spread our feet to widen the base support.
Differentiate Qout and Qin?
Qout is heat wasted while Qin is heat absorbed.
Differentiate Thot and Tcold?
Thot is air from hot reservoir while Tcold is air from cold reservoir.
Define heat engines?
They need air from hot reservoir in order for work to be done, then the excess heat goes to the exhaust, resulting to a lower temperature.
Define heat pumps?
They need work to be done for cold air to be transferred to hot area.
