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Mechanics
Mechanics is the branch of physics that deals with the interactions of objects and forces in the observable world. Questions asking about projectile motion, conservation of energy, and calculus based mechanics are perfect for this topic, but questions about repairs that a mechanic would do belong in our vehicles categories.
2,416 Questions
Assuming you want the international units:
time: second
velocity: meters / second
distance: meters
acceleration: meters / second2
The wavelength is compressed by the additional velocity of the car, so the frequency heard is higher than that generated in the horn.
It's known as the Doppler Effect.
What is happening to an object if it's net force is zero?
Net Force is equal to the product of mass and acceleration.F = ma, where m is mass and a is acceleration
When a net force is 0.
0 = ma, so either m has to be or or a has to be 0 because of the zero factortheorem.
Mass is not going to be zero, therefore acceleration must be zero.
When acceleration is zero, that means it is neither speeding up nor slowing down, but it could still be moving.
What is the net force when you combine a force of 9 N with a force of 4 N south?
It could be anything between 5 N and 13 N, depending on
the direction of the 9 N component.
What is the net force when you combine a force of 13N to the north and 17N to the south?
Take north to be the positive direction, and south to be the negative direction.
Net force = 13N + (-17N) = -4N
Net force = 4N to the south.
Give an example of a first class lever?
Third class levers the Effort is between the Resistance and Fulcrum (FER)
Examples are:
· Mouse trap
· Baseball bat
· Tweezers
· Nail clippers
· Mandible
· Hockey Stick
· Fishing Rod
· Door
· Broom
· Arm
· Boat Paddle
When force is to the direction of motion no work is done?
No. Only if you are applying the same amount of force then there is no motion. If you are applying more force (the object is moving) then there is work being done.
How one can increase the force of friction?
there are a few different things that come to mind immediately. The most prevalent being changing one or both of the surfaces making contact. for instance, rubber (as in a tire, most often) on clean, dry pavement has a static friction coefficient of 0.9 μs while rubber (again as in a tire) on wet pavement has a static friction coefficient somewhere in the ballpark of 0.25-0.75 μs.
the static (and kinetic, for that matter) coefficient of friction varies between almost every pair of materials (some may be close if the surfaces are similar).
additionally, the force of friction would increase the greater the mass of the object that the force is being applied to. the force of friction is calculated as follows;
Ff = μ · N
where Ff is force of friction, μ is the coefficient of static friction, and N is the normal force (normal force is equal to the mass of the object times the acceleration of gravity. the unit of measurement for this value is newtons, and it is simply the weight of the object) Given this equation, you can see that by increasing the mass of the object, you are in effect increasing the frictional force acting on that object.
hope this helped!
Elasticity is a physical propery of materials which permit the return to the initial state after the cessation of a deforming action.
What factors affect the speed of a falling object?
Factors that increase speed of a falling object:
HEIGHT - The longer an object is in the air the more speed it gains due to gravity
GRAVITY - The strength of the acelleration due to gravity (eg the moon is different to earth)
STARTING VELOCITY - The speed the object starts at.
Factors that decrease the speed of a falling object:
AIR RESISTANCE - Air resistance is a major factor however it in itself is dependant on the air pressure around the object and the surface area of the object.
Can you use PTFE to avoid friction in between 2 blocks when running coated material through blocks?
Maybe.
Any lubricant that doesn't react with the surface coating will work between the blocks. Dry lubricants (soaps, graphite, waxes...etc.) or wet lubricants (oil, glycerine, water, soaps...etc.) work well to varying degrees depending on the materials they lubricate and whether the lubricant and the surfaces react adversely under heat and pressure. Consulting a lubrication specialist, (most lubricant manufacturers consult with customers for the best match), for your best results. PTFE can breakdown under high pressure and high temperatures and usually is not great for high speed high temperature operations but works great at low speed and/or low pressure applications, and it does not react adversely with most materials.
Who founded experimentally that the speed of a falling object is not proportional to its weight?
Galileo Galilei
Why friction should be reduced?
friction is a necessary evil for the man-kind although it has many advantages it also carries any dis-advantages with it which are discussed below :-.
1. it reduces the efficiency of any machine, as some of the energy is lost due to friction as heat energy.So the energy reaching the output would be {input energy - frictional energy}
2. it causes wear and tear of machines.
3. produces unnecessary heat.
when you walk on pebble on the beach the sand doesn't flow.it is not moved by any source.so the normal reaction force that you exert on the ground results in more pressure as surface area of pebbles is less.but when you enter the sea pebbles slide past each other because of the motion of water.thus the pebbles don't remain in their position and our foot digs a little deeper,thus reducing the pressure.
What kinds of mixtures can be separated by distillation?
Fluid mixtures, and mixtures of substances in different phases, that differ in their boiling points, can be separated by distillation. For instance:
Sand and water (solid/water mix) by evaporating (distilling) the water away from the sand.
Alcohol and water (liquid/liquid solution) can be fractionally distilled, collecting the alcohol first and then the water, which boils at a higher temperature.
CO2 and water (gas/liquid solution) can be be fractionally distilled also.
Evaporating sea water (solid/liquid solution) to crystallize the salt, although, this leaves a mixture of salts which can't be separated by normal distillation.
