What is motion? An object is in motion if its distance from another object is changing. (CHANGE IN POSITION) Ex. drag racing, Fast and the Furious, san antonio speedway, indy 500, Days of Thunder Motion

An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This law is often called "the law of inertia". still still blazin’ by unbalance force Newton’s First Law of Motion

What is distance? The change in position Ex. traveling from San Antonio to Houston 515 miles Distance

What is Displacement? is the distance and direction between starting and ending positions. Ex. SA to Dallas = 275 miles Dallas to Houston = 240 miles Total distance = 515 miles Total displacement= 198 miles Displacement

What is speed? the distance an object travels in a specific amount of time. Distance (m) Speed (m/s)= time (s) Speed

A hockey puck slides along the ice for 3 seconds before crossing the goal line 6 meters away. What is the average speed of the puck before it crossed the goal line? Question?

What do you know? Distance = 6 meters Time = 3seconds Speed = distance / time Speed = ____ m/s Answer

If you run 3 km in.5h your speed is…. speed = ______ / ________ speed = _____ km/h A swimmer takes 40s to swim 100m. What is his or her average speed? = _______ STOP Questions

What is velocity? How fast something is traveling -the direction and speed an object travels (straight line) Displacement (km) Velocity (km/h)= time(h) Velocity

If you were to travel 1 km east in.5 h, what is your velocity? Displacement (km) Velocity (km/h)= time(h) = _____km h velocity = ________ km/h stop Question

What is slope? the steepness of a line on a graph. ( RISE ) SLOPE= RUN Slope

What is acceleration? -the rate at which velocity changes over time (speed and/or direction). (final speed (m/s)– initial speed (m/s)) Acceleration (m/s 2 ) = time (s) Acceleration

Acceleration is positive when an object is speeding up (acceleration) Acceleration is negative when an object is slowing down (deceleration). Acceleration is typically measured with units of meters per second squared (m/s 2 ) or feet per second squared (ft/s 2 ).

If you hold a ball in your hand a drop it to the floor. From being at rest (0 speed) to moving at 29.4m/s in 3s. What is the acceleration of the ball? Question

What I know: Initial speed = 0 m/s Final speed = 29.4 m/s Time = 3s (final speed (m/s)– initial speed (m/s)) Acceleration (m/s 2 ) = time (s) Solve: = _______ m/s 2 Answer

9.8m/s 2 STOP

The net force on an object is equal to the mass of the object multiplied by the acceleration of the object. The second law is usually summed up as an equation: Force (N) = Mass (kg)(g) x Acceleration Acceleration (N/kg)(m/s 2) = Force (N) / Mass (kg)(g) If the force placed on an object is doubled, the acceleration of the object will also be doubled. If the mass of an object is halved, the acceleration on the object is doubled (when the force remains the same). An example of this law would be if a bowling ball and a soccer ball were dropped from the same height at the same time. Gravity accelerates the objects at the same speed (as it does for all objects), so the difference in forces as the balls hit the ground would be due to the mass of the ball. Thus, the bowling ball, which has the larger mass, would hit the ground with a greater force. Newton’s 2 nd Law

Gravity weight is 9.8m/s 2 Weight (N) = mass (kg) X acceleration due to gravity (m/s 2 ) If your mass was 60kg. On earth you would weigh: Weight = 60kg x 9.8m/s 2 =588N Gravity

How much force is needed to accelerate a 1,000 kg car at a rate of 5 m/s 2 ? A. 7,500 N B. 2,500 N C. 1,000 N D. 5,000 N A cart is rolling across the floor at a constant velocity of 2 m/s to the right. The cart is pushed again to the right, and it starts to accelerate. How are the force of the push and acceleration of the cart related? A. The force of gravity makes the car accelerate. B. The force and acceleration are not related. C. The balanced push causes the cart to accelerate. D. The unbalanced push causes the cart to accelerate. Question

A child has a mass of 71kg. Her bike has a mass of 9kg. The bike and rider are accelerated at a rate of 3.2m/s 2. Find the force used to accelerate the bike and the rider. Question

Acceleration: a = 3.2m/s 2 Mass:71kg + 9kg = 80kg F = MA F= 80kg * 3.2m/s 2 = 256N Answer

-a force that resists motion between surfaces that are touching. Types of Friction Static Friction (carpet) Sliding friction (pull paper under a book) Rolling friction (skateboarding, tires) STOP What is Friction?

For every action, there is an equal and opposite reaction. Whenever object A exerts a force on object B, object B exerts an equal force (in the opposite direction) on object A. Both forces are exerted along the same line. For example, when a bird flies, its wings push downward on the air. The air then pushes upward on the wings (and the bird). The action of the bird flapping its wings (exerting a force on the air) helps the bird fly (the air exerting a force on the bird). Newton’s 3 rd Law

Opposite Reaction

-are tools that make work easier. One way simple machines make work easier is by reducing the amount of input force needed. Another way simple machines make work easier is by changing the direction of the input force. inclined plane - An inclined plane is a flat surface that is slanted. Inclined planes reduce the size of the input force needed for a task by increasing the distance through which the force is applied. A wedge is a double inclined plane. A screw is an inclined plane wrapped around a shaft. lever - A lever is a rigid object that pivots around a point. The pivot point is called the fulcrum. A lever can reduce the amount of input force needed for a task by increasing the distance through which the force is applied. A seesaw, crowbar, wheelbarrow, and the human arm are all examples of levers. wheel and axle - A wheel and axle consists of an axle attached to the center of a wheel. It reduces the size of the input force needed for a task by increasing the distance through which the force is applied. When the wheel is turned, the axle is turned in the same direction. Because the wheel has a larger radius than the axle, the wheel moves a greater distance than the axle. As a result, the input force needed to turn the axle is reduced. pulley - A pulley is a rope threaded through a wheel or disk. It is used to lift objects. A pulley changes the direction of the input force. A pulley system, which consists of multiple wheels, can also reduce the size of the input force. A flagpole is an example of a pulley. Simple Machines

It is important to note that while simple machines can reduce the amount of force needed to perform a task, they do not reduce the amount of energy or work needed to perform a task. For example, a ramp (inclined plane) reduces the amount of force needed to lift an object, but it increases the distance through which the force is applied. So, simple machines do not reduce work; they make work easier. Conservation of Energy

An inclined plane is a flat surface that is slanted. Inclined planes reduce the size of the input force needed for a task by increasing the distance through which the force is applied. Inclined Plane

A screw, like a wedge, is another form of an inclined plane. A screw is an inclined plane wrapped around a cylinder to form a spiral. Screw

A wedge is an inclined plane which moves. Most wedges (but not all) are combinations of two inclined planes. A knife, axe, razor blade, and teeth are all good examples of wedges. Generally it can be anything that splits, cuts, or divides another object including air and water. Wedge

A lever is a rigid bar that turns or pivots around a fixed point called a fulcrum. All levers contain a resistance arm, an effort arm, and a fulcrum. Levers

A wheel and axle is a lever that rotates in a circle around a center point or fulcrum. The larger wheel (or outside) rotates around the smaller wheel (axle). Bicycle wheels, ferris wheels and gears are all examples of a wheel and axle. Wheels can also have a solid shaft with the center core as the axle such as a screwdriver or drill bit or the log in a log rolling contest. Wheel and Axle

A pulley is a chain, belt or rope wrapped around a wheel. The mechanical advantage of a pulley system is approximately equal to the amount of supporting ropes or strands. Pulley

-are two or more simple machines working together. A wheelbarrow is an example of a complex machine that uses a lever and a wheel and axle. Machines of all types make work easier by changing the size or direction of an applied force. The amount of effort saved when using simple or complex machines is called mechanical advantage or MA. Compound Machines

-wheel and axle -levers -inclined plane -pulleys