Show:
Describing Motion
Acceleration
Motion and Forces
Newton's Laws of Motion
Word Problems
100
What is the formula to find the Average Speed of an object?
v = d/t
100
What is the difference between positive and negative acceleration?
If speed increases, then acceleration is positive. If speed decreases, then acceleration is negative.
100
What does the force of friction between two objects in contact depend on?
It depends on the kind of surface and the force pressing the two objects together.
100
What of Newton's Laws of Motion states that for every action (or force), there is an equal and opposite reaction (or force)?
Newton's Third Law of Motion
100
A mouse walks at a speed of 4 kmph. How much time does it take to walk a distance of 20 km?
time = distance / speed t = 20 km / 4 kmph t = 5 hours
200
What is motion?
Motion occurs when an object changes position relative to a reference point.
200
What is the difference between speed and velocity?
Velocity includes how fast an object is going and the direction of its motion, whereas speed does not include direction.
200
What is net force?
Net force is when two or more forces act on an object at the same time.
200
What is momentum?
Momentum is the property of a moving object resulting from its mass and velocity.
200
A cyclist covers a distance of 16 miles in 2 hours. Calculate her speed.
speed = distance / time v = 16 miles / 2 hours v = 8 miles per hour
300
What is distance?
Distance is how far an object has traveled.
300
What is acceleration?
Acceleration is the rate of change in velocity?
300
What is friction? What causes friction?
Friction is the force that opposes the sliding motion of two touching surfaces. Microwelds, tiny microscopic bumps on surfaces, cause friction.
300
Which of Newton's Laws of Motion states that acceleration is determined by size of force and the mass of an object?
Newton's Second Law of Motion
300
A car takes 4 hours to drive from Los Angeles to Ensenada. If it travels at a speed of 70 miles per hour, how many miles did the car drive?
distance = speed x time d = 4 hrs x 70 mph d= 280 miles
400
What is displacement?
Displacement is the distance and direction of an object's change in position from starting point.
400
What is the formula for calculating acceleration?
a = Vf - Vi / t
400
Name the four different kinds of friction and explain what they are.
STATIC - Friction in which two surfaces are not moving past each other. SLIDING - Friction where two surfaces slide past one another. ROLLING - Friction between a rolling object and surface it rolls on. FLUID - Friction when object moves through fluid, meaning either a liquid or gas
400
What is the Law of Inertia?
The Law of Inertia is also known as Newton's First Law of Motion. It states that an object in motion stays in motion, or an object at rest stays at rest until an unbalanced net force acts upon it.
400
A woman rode her motorcycle at 10 m/s. After catching a yellow light, she sped up for 2 seconds to avoid running a red light and reached a speed of 16 m/s. What was her acceleration?
a = (Vf - Vi) / t a = (16 m/s - 10 m/s) / 2 s a = 6 m/s divided by 2 s a = 3 m/s^2
500
What is speed? What are the 3 different kinds of speed?
Speed is the distance an object travels per unit time. The different types of speed are instantaneous speed, average speed, and constant speed.
500
Give an example of positive and negative acceleration.
Positive acceleration = a plane takes off Negative acceleration = a bicycle comes to a stop
500
What is a friction-like force that opposes motion of objects that move through air?
Air resistance
500
In the lab "Newton's Racers," we were able to see all three of Newton's Laws of Motion in action. Describe ONE instance when there was an example of one of these laws. What happened?
Newton's 1st Law: the air coming out of the balloon is the force needed to make the balloon move Newton's 2nd Law: the more force (air) applied to the balloon, the more it will change in motion (or the farther it will go) Newton's 3rd Law: the air pushed against the balloon (action) is what made the balloon propel forward (reaction)
500
A cat is running on a fence at 6 m/s. She then jumps off and comes to a complete stop. This took 2 seconds. What was her acceleration?
a = (Vf - Vi) / t a = (0 m/s - 6 m/s) / 2s a = -6 m/s / 2s a = -3 m/s^2