Unit 4: Physics

Unit 4: PhysicsTest Review

When all __forces _acting on an object are not equal and it will cause a change in the object's motion.

And give an exampleUnbalanced Forces

The distance an object travels in a specific time.

SpeedIf a boy runs 100m in 20 seconds, how fast is he going?

Speed=Distance/Time (m/sec) divide Speed = Distance 100m = 5 m/sec Time 20sec

Speed in a given direction.

Give an EX:

VelocityThe rate at which velocity changes.

Give an EX:AccelerationA soccer ball will slow down as it travels across a grassy field

If a car travels 400m in 20 seconds, how fast is it going? (Show formula, work and units)

Speed=Distance/Time (m/sec) divide Speed = Distance 400m = 20m/sec Time 20sec

You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel? (Show formula, work and units)

Speed = Distance/Time (m/sec) Speed = Distance 90m = 2m/sec Time 45sec

_____________energy is the energy of an object due to its positionGive an EX:Potential Energy_____________energy is energy due to its motion.Give an EX:Kinetic EnergyDraw a roller coaster track and label with the greatest potential and greatest kinetic energy.

W greatest potential energy and X greatest kinetic energy.

Mr. Terry pushes with a force of 18N. The frictional force pushes back with 12N of force.

12 N18 NMovement to the left with 6 N of forceDevices that reduce the amount of force or direction of a force needed to move an object. Simple MachinesWhy do people use simple machines? Be detailed in your answer.People use simple machines so that the amount of force exerted to move an object decreases as they use a simple machine, ex. a longer ramp (inclined plane) or a pulley

Why are pulleys useful? Draw a picture that demonstrates the correct way a pulley works when applying force.They change the direction of the force acting on the object

When an object's distance from another object is changingMotion

How can you tell if an object is in motion?A reference point is a place or object used to determine if something is in motion. (The fence is a reference point in this picture)

Why is an inclined plane considered a simple machine?It reduces the amount of force needed to move an object

Would a shorter or longer inclined plane be more helpful? Why?A longer ramp would be more helpful because as the length of the inclined plane increases, the amount of force needed to lift the load decreases.

On a distance-time graph, time is always graphed on which axis?

X-AxixWhat kind of line represents constant speed on a distance-time graphA STRAIGHT line is used to show constant speed

What does a line with a steep slope represent on a distance-time graph.

The STEEPER the line the FASTER the speed

What kind of line represents acceleration or deceleration on a distance-time graphA CURVED line shows acceleration or deceleration