TAKS REVIEW PHYSICS

OBJECTIVE 5 The student will demonstrate an understanding of motion, forces and energy. –Calculations –Newton’s Laws –Mechanical Advantage –Waves –Conservation of Energy –Heat –Energy Sources –Circuits

Formula Chart Formula in words Formula in symbols: use them!! ConversionsConstants

Newton’s Laws Newton's First Law of Motion, or Law of Inertia –object will remain at rest or move with constant velocity when there is no net force acting on it. –Newton's First Law deals with an object with no net force If there was no friction, air resistance, etc

Newton’s Laws Newton’s second law of motion. –describes the effects of unbalanced forces on the motion of objects. –Force = mass x acceleration F = ma –Units:Force = Newtons (N) or (kg x m/sec 2 ) A force is required to change motion of an object.

Newton’s Laws Newton's Third Law of Motion –when one object applies a force on a second object, the second object applies a force on the first that has an equal magnitude but opposite direction. –action-reaction forces. Rockets, rowing a boat, kicking a soccerball

Mechanical Advantage Investigate and demonstrate mechanical advantage and efficiency of various machines such as levers, motors, wheels, axles, pulleys and ramps

WAVES Demonstrate wave types and their characteristics through a variety of activities such as modeling with ropes and coils, activating tuning forks and interpreting data on seismic waves Wave equation v = f λ (velocity = frequency x wavelength)

WAVES TRANSVERSE –Particles perpendicular to motion of wave –Light –“The wave”

WAVES LONGITUDINAL –Particles move parallel to motion of wave –Sound –Compression and rarefaction

WAVE INTERSCTIONS Constructive: positive net result

WAVE INTERACTIONS DESTRUCTIVE: negative net results (cancel out waves)

Seismic waves Primary waves (P waves) are longitudinal waves Secondary waves (or S waves) are transverse waves Surface waves travel along the boundary between the ground and the air. They are the slowest type of seismic wave, but they can do the most damage.

S & P waves

Heat The heat of an object is the total kinetic energy of its molecules KE = ½ mv 2 Temperature of the object is the measurement of the average KE of its molecules Temperature of the object is the measurement of the average KE of its molecules Specific heat is a way to compare heat from different materials. Heat energy Specific heat is a way to compare heat from different materials. Heat energy Can cause expansion in many materials. Can cause expansion in many materials.

Sources of heat energy Light Chemical Reactions Electrical Resistance Friction Nuclear reactions

Heat Transfer Conduction – direct contact –conductors (metals) –insulators ( wood, plastic, air) Convection – movement through fluids (air is a fluid) –density differences, warm air rising Radiation - the transfer through empty space – heat from the sun

Energy Sources Investigate and compare the economic and environmental impact of using various energy sources such as rechargeable or disposable batteries and energy cells

Circuits Investigate and compare series and parallel circuits Series: several electrical devices such as light bulbs can be placed in a line or in series in the circuit between the positive and negative poles of the battery One pathway for current to travel

Circuits Parallel: Two or more paths for circuit to travel

Ohm’s Law Current = voltage / resistance

Sample problems The picture shows a cube that contains 20 mL of a solution. The solution has a mass of 40 grams. What is the density in g/mL of this solution? Record and bubble in your answer on the answer document. 2.0 g/ml

The illustration above shows a student about to throw a ball while standing on a skateboard. Which illustration below correctly shows the skateboard’s direction of motion after the student releases the ball?

Which bike rider has the greatest momentum? A A 40 kg person riding at 45 km/h B A 50 kg person riding at 35 km/h C A 60 kg person riding at 25 km/h D A 70 kg person riding at 15 km/h

Observing an approaching thunderstorm and using a stopwatch, a student finds that it takes 8.40 seconds for thunder to be heard after a lightning bolt strikes. The student has learned that it takes 3.0 seconds for sound to travel 1000 m. How far away is the storm? F 119 m G 185 m H 2800 m J 8400 m

As a scuba diver goes deeper underwater, the diver must be aware that the increased pressure affects the human body by increasing the — A body’s temperature B amount of dissolved gases in the body C amount of suspended solids in the body D concentration of minerals in the body

What is the mass of a mL sample of seawater with a density of g/mL? F g G g H g J g d = m/v m = dv

An ant crawled from Point A to Point B in 4.0 seconds. To the nearest tenth, what was the ant’s speed in centimeters per second? Record and bubble in your answer on the answer document.

Which of the following objects will float on water? WATER d= 1.00 g/cm 3

A man who was sleeping wakes up because he hears the smoke alarm go off in his house. Before opening the bedroom door, the man feels the door to see whether it is warm. He is assuming that heat would be transferred through the door by — A conduction B convection C radiation D compression

Which illustration best demonstrates compression waves?

The graph shows the distance traveled by a vehicle over a certain period of time. Which segment of the graph shows the vehicle moving with the greatest speed? A L B M C N D O

In a movie, meteoroids make several microscopic holes in a pressurized cabin in the weightless environment of a spaceship. The astronauts search for the holes by spraying water droplets from a container. If this were an actual situation, what effect should be expected? F The drifting water droplets float to the location of the holes. G After falling to the floor, the water forms a stream leading to the holes. H The water droplets form a large sphere of water that moves away from the holes. J Pumping the trigger on the spray container increases the air pressure in the cabin.

The cloud conditions above are typical of locations near a warm front. According to these data, what are the most likely sky conditions for Waco? A Cirrus clouds C Stratus clouds B Altostratus clouds D Clear skies

A cold front moves from Abilene to College Station in 6.0 hours. What is its average speed in km/h? F km/h H 58 km/h G 16 km/h J 67 km/h

Which circuit is built so that if one light bulb goes out, the other three light bulbs will continue to glow?