# Physics: 1-5.txt

 translational motion: distance, velocity, acceleration. time x = x0 + v0t + (1/2)at2 translational motion: velocity, acceleration and distance v2 = v02 + 2ax translational motion: velocity, acceleration and time v = v0 + at how does a projectile stay in motion? what keeps it in motion? inertia peak height of a projectile v0 = sin(0) - sq.rt.(2gh) horizontal distance traveled of a projectile x = vt . cos(0) peak velocity no velocity, but acceleration = 10 PE and KE of projectile object at its peak PE is maximizedKE is minimized (energy must be conserved) projectile path is independent of.... mass two objects launched with the same velocity will... hit the ground at the same moment what determines the time of flight? vertical velocity range of projectile is maximized at what angle from the horizontal? 450 symmetry of projectile says what? (speed wise) upward mirrors downward - initial speed = final speed air resistance is greater on (surface area, shape, and speed) larger surface areairregularly shapedgreater speed does mass affect force or path of air resistance force = no path = yes how does greater mass affect air resistance force is the same, so it decreases acceleration (F=ma) centripetal force (equation) F = m . v2/r inertia tendency of an object to stay in present state of motion (keeps projectile in motion) law of universal gravitation F = G(m1m2)/r2 friction points in what direction? always parallel to surface equation for torque t = F r sin0 if the board has mass, what do you do with torque? F=mg at center of board equation for work (not for gases) W = Fd cos0 what direction is friction (relative to work)? friction does negative work! work done lifting an object W = Fd = mg x h what is gravitational potential energy? work done by gravity: change PE = -W energy and power energy = work + heat so, P = (w + q)/s 1 revolution is equal to 2 pi r equation for angular momentum L = l x m x v l = lever arm, mv = linear momentum elastic collision mechanical energy is conserved inelastic collision mechanical energy is lost to internal energy (heat) perfect inelastic collision 2 objects stick together reverse inelasitc collisions (object dissipates into 2 sep. objects). In what direction do they travel opposite to each other ex: man standing on a board and jumps off what do you need to consider when determining their final positions? move in opposite directions consider their centers of gravity what is impulse? change in momentum Machine: inclined plane (how is work minimized?) straight up: W = ugh ramp: W = mg x sin x h What is theta equal to in the ramp height of ramp / distance of the ramp the greater the distance (d) the smaller the angle, the less work needed Machine: lever (torque) what does F need to equal to lift mass? F = mg in opposite direction How do you decrease the force required to life the object? increasing the lever arm (doubling lever arm, reduces force by a factor of 2) In a pulley, what is the tension in the rope? constant Tension = Force In a double pulley system, what is the force required to lift mass m? F = T T = 2mg F = (mg)/2 alpha decay 2 protons, 2 neutrons traveling of alpha particle not far stopped by skin, paper beta decay expulsion of an e- positron B+ is emitted (-1 atomic #) electron capture gain e- (-1 atomic number frequency of a gamma particle high frequency particle rest mass energy E = mc2 fussion combining 2 (?) from (?) combining 2 nuclei from a heavier nucleus fission splitting a single nucleus into 2 lighter nuclei where does energy for fusion and fission come from? mass defect density formula density = m/v density constant for gases and liquids? constant for liquids and solids change for gases, because they are compressible What is specific gravity? density of a substance compared to density of water so specific gravity of water is 1 formula for fluid pressure P = F/A Do fluids at rest have uniform density in a sealed container? yes What is the pressure experience by fluids at rest with uniform density? P = density x g x y y = depth of fluid Where is pressure greatest for a fluid at rest? greatest depth (P=pgy) What if you have many fluids layered in a sealed container? P = (pgy)1 + (pgy)2 + (pgy)3........... What is the pressure of a fluid at rest with uniform density in an open container add atmospheric pressure to density x g x y hydraulic lift (equation) pressure is transferred completely: F1/A1 = F2/A2 What is the velocity of a fluid flowing (if you don't know rate or area)? v = sq.rt (2gh) buoyant force upward force acting on a submerged object what is buoyant force equal to? (not equation) weight of fluid displaced by submerged object equation for buoyant force FB = (density of fluid) x (volume) x (g) floating object - submerged portion of object = density of object/density of fluid How much of an object will float in water if its specific gravity is 0.4? 60% does buoyant force change with depth? No What is the apparent mass on an object (when it is submerged)? mass of the fluid displaced thats why we weigh so little in water equation for fluid flow Q = (area)(volume) does fluid flow faster in a wider pipe, or a more narrow pipe? narrow ideal fluid flows at a constant rate K = Pressure + (density)(g)(h) + (1.2)(p)(v2) K is constant, specific to fluid in a flow surface tension and temperature increase temperature = weaker surface tension formula for stress force/area formula for strain change in dimension/original dimension what are stress and strain stress is done on an object strain is how the object responds modulus of elasticity stress/strain Authornatalieplana ID82962 Card SetPhysics: 1-5.txt DescriptionLectures 1-5 Updated2011-05-01T15:12:46Z Show Answers