Advance ahead 1
What is the mathematical formula that can
be used to determine the force applied to an
object?
Force = mass x acceleration
How does a fidget spinner demonstrate
Newton’s first law of motion?
The fidget spinner is at rest and will remain at rest until an unbalanced force acts on it. When you apply a force to it, it begins spinning and remains in motion until friction and air resistance slows it to a stop.
Identify which of Newton's Laws best explains why seat belts reduce injuries in car crashes, and briefly explain why.
Seat belts reduce injuries because a person will continue forward due to their inertia (1st law) in a car crash, with restraints the person will be pulled back in the opposite direction with the seatbelt which is Newton's 3rd law.
Which law is it? When the passenger presses against a seat belt, the seat belt presses back against the passenger with equal force in the opposite direction.
The Third Law
The more mass an object has, the more force
is needed to _____________ it. Fill in the blank.
The more mass an object has, the more force
is needed to _ACCELERATE (move, change direction) it.
Which of Newton’s laws explains why a TV
flies off the car when it stops? Explain.
Newton’s first law—the TV has inertia due
to the car’s motion.
When it stops, the TV will continue
forward at the same speed and in the
same direction.
Describe the simultaneous force pairs in shooting a basketball.
Action: The basketball hits the
backboard.
Reaction: The backboard exerts an equal
force on the ball.
Which law is it? It takes more force to accelerate plates of larger mass than to accelerate plates of smaller mass.
This is the 2nd law.
A car accelerates when the traffic light turns
green. Which of Newton’s laws can be
applied to this scenario?
ALL 3 LAWS:
The car accelerates which is a change in speed or the 2nd Law a force large enough to over come the mass is needed. The car has an unbalanced force applied to accelerate, the 1st law. The car applies a force on the ground while the ground applies an equal and opposite force upward.
How do unbalanced forces affect the motion
of objects?
Unbalanced forces can change direction, speed up, slow down or stop an object's motion.
How is frequency measured?
The number of waves per period of time.
According to Newton’s second law, how
would your acceleration change if you
continually increased your bouncing force as
you jumped on a trampoline?
Your acceleration will increase as your
bouncing force increases (i.e., the harder
you jump, the higher you will go).
A hockey puck glides across the ice after
being struck by a hockey stick. It continues
moving forward until friction and air resistance
slow it down. Which law is it?
This is the 1st law.
Two tectonic plate converge resulting in an earthquake. How does Newton's 1st law apply?
Tectonic plates will remain at rest or in
motion until an unbalanced force acts on
them.
An amusement-park ride spins riders in a circle. Explain which law causes passengers to feel pushed outward (their tendency).
The 1st Law applies here. The passengers' inertia causes them to continue in the same direction (straight) as the ride turns.
A net force of 20N acts on a mass and produces an acceleration of 4 m/s2. What is the mass?
20N / 4 m/s2 = 5 kg
Describe the relationship between the amplitude and the intensity of a wave.
Higher amplitude waves have higher intensity.
How do Newton's laws apply when a roller coaster goes down the tracks?
The roller coaster will continue at the same speed and direction until an unbalanced force acts on it.
If a 2 kg toy car accelerates at 3m/s2 . What is the net force on the car? Show calculation.
F=ma
Force = 2kg x 3m/s2
Force = 6 N
Two waves traveling in the same medium have the same wavelength and frequency, but one has a larger amplitude than the other. Which characteristic differs between the two waves, and what does that difference represent?
Amplitude; it represents the wave's energy or intensity.