a push or pull on an object
What is Force?
What is the net force and direction of motion?
0 N, no movement
What is Newton's 1st Law?
An object at rest will stay at rest; an object in motion will stay in motion unless acted on by an outside force
A dog with a mass of 12 kg accelerates at a speed of 8 m/s2. How much force does the dog have?
F = m x a
96 N
change in an object's position over time
What is the net force and direction of motion?
10 N to the right
What is Newton's 2nd Law?
F = mass x acceleration
or
F = m x a
A 115 N force causes a mass to accelerate at 9.8 m/s2. What is the mass of the object?
m = F/a
11.7 kg
the sum of all forces acting up on an object
What is Net Force?
What is the net force and direction of motion?
4820 N to the left
What is Newton's 3rd Law?
Every action has an equal and opposite reaction or every force has an equal and opposite force
You kick a soccer ball weighing .6 kg with a force of 70 N. What was the acceleration of the ball?
a = F/m
117 m/s2
a change in speed or direction
What is acceleration?
What is the net force and the direction of motion?
114 N to the left
Which of Newton's Laws is described in the following example?
You hit a boxing bag sitting at rest. It swings away from you.
Newton's 1st Law (object at rest stays at rest until acted on by an outside force)
You run for an hour and 12 minutes. In that amount of time, you travel 7.8 miles. What was your average speed in miles per minute (distance/time)?
7.8 miles/72 minutes = .11 mile/minute
equal forces acting in opposite directions on an object
What is an unbalanced force?
Draw a net force diagram that results in a 24 N force to the North.
Example:
Which of Newton's Laws is described in the following example?
A man gets hit in the face with a soccer ball. His head moves to the right while the soccer ball drops to the left.
Newton's 3rd Law (every action has an equal and opposite reaction)
A boxer hits a wall with a force of 50 N. Due to Newton's 3rd Law, the wall pushes back with an equal and opposite force. The boxer wears gloves that absorb 40 N.
How many Newtons does the boxer feel in his hand?
10 N
50 N force from the wall - 40 N absorbed into the gloves = 10 N
You squeeze a stress ball. It compresses. When you release it, it returns to its original shape.
Choose one of Newton's Laws and explain how it is demonstrated by this motion.
Newton's 1st Law - The stress ball is at rest and does not compress (move) until you apply a force.
Newton's 2nd Law - You apply a force to a mass and it accelerates (by moving in on itself)
Newton's 3rd Law - The action is squeezing the ball and making it compress; the reaction is the ball pushing back and expanding to its original shape.