Physics 7th Grade – Newton’s Law
State which of the following statements is TRUE or FALSE!
1) A less massive object has more inertia than a more massive object.
2) When you step on a roach, the roach applies an equal and opposite force on
your foot as your foot applies to the roach (we don't advocate killing insects this
way, especially if you are barefoot).
3) Objects in orbit around the Earth (like a satellite) still have net forces acting on
them.
4) A stationary object has no forces acting on it.
5) An object's inertia causes it to come to a rest position.
6) When a large truck pushes a small car with a given force, the small car is
applying an equal and opposite force on the truck.
7) When an object is stationary, all of the forces acting on it are balanced.
8) The only way to slow down a moving object is to apply a net force to it.
9) An object that is not accelerating or decelerating has no net forces acting on it.
10) Objects tend to stay moving because of a force called inertia.
Mutiple Choice
11) Which of Newton's Laws gives the reason for why you can feel things that you
touch?
a) First Law
b) Second Law
c) Third Law
12) A horse pulls forward on a carriage with a given force. By Newton's Third Law,
the carriage must be pulling on the horse backward with an equal and opposite
force. Given this, what explains why the horse and carriage can move forward?
a) The cart's force is only in reaction to the horse's force so it does not define
direction of movement
b) The cart is rolling on wheels while the horse's hooves have traction with the
ground
c) The forward and backward forces are equal, so it actually can't move
forward
d) There is a brief moment where the horse pulls before the reaction force kicks
in
13) Which best explains why we are able to accelerate forward when starting to
run?
a) As one leg moves backward, it provides an equal and opposite force for the
other foot to move forward.
b) The striking foot pushes backward against the ground. The friction with the
ground provides an equal and opposite force forward.
c) The foot not touching the ground propels the entire body as it swings forward.
d) The runner’s upper body quickly leans forward, causing the entire body to begin
accelerating forward.
14) You and a friend are pulling on a rope in opposite directions as hard as you
can. What is the "equal and opposite force" to the force of your hand pulling on
the rope described by Newton's Third Law?
a) The force of friction between the ground and your shoes
b) The force of the rope pulling your friend's hand
c) The force of the rope pulling on your hand in the opposite direction
d) The force of your friend pulling on the rope in the opposite direction
Short Question
15) A 200-kg object has a 50-Newton rightward net force being applied to it. What
is the magnitude of the rightward acceleration on the object (in m/s2)?
16) A 7- kg object is accelerating to the right at 2 km/s2 What is the magnitude of
the rightward net force acting on it?