Newtons Laws
A passenger lurches forward when a car suddenly stops. Which law explains this and why?
→ What is Newton’s 1st Law because the passenger’s body wants to stay in motion even though the car is being acted on by an outside force.
The unit used for all types of force.
Newtons
A 2 kg object moves at 3 m/s. A 6 kg object moves at 1 m/s. Compare their momentum.
→ They are equal (6 kg·m/s)
Frictional force and normal force produce what type of graph pattern?
What is Linear.
A 50 kg student accelerates at 2 m/s². What force is required?
→ What is 100 N.
This law explains why kicking a ball harder makes it go farther.
→ What is Newton’s 2nd Law?
The resistance an object experiences when moving over another surface.
Force of Friction
In a closed system, object A loses 15 kg·m/s of momentum. What must happen to object B?
→ It gains 15 kg·m/s.
Explain why Impact force has an Inverse Relationship?
What is, As the time of Impact increase the Force of Impact with decrease.
A 2,000 kg car has a weight of 20,000 N (g = 10).
If μ = 0.5, find friction force.
What is 10,000 N
A rocket pushes exhaust gases downward. Explain how this allows the rocket to move upward.
→ Newton’s 3rd Law — exhaust gases push down, rocket experiences equal and opposite upward force.
Why is weight considered a force, but mass is not?
→ Weight depends on gravity and is measured in Newtons; mass is amount of matter measured in kg.
Why does a truck experience less acceleration than a car in a collision even though the forces are equal?
→ Because the truck has greater mass (F = ma).
Frictional force follows this pattern when graphed against normal force.
→ What is linear?
A 0.5 kg ball moving 8 m/s is stopped in 0.2 seconds.
Find impact force.
→ 20 N.
This law states that acceleration depends on force and mass.
→ What is Newton’s 2nd Law?
The increase or decrease of an object’s speed = ________
The power an object has based on its mass and velocity = _________
Acceleration
Momentum
After a collision, total system momentum is conserved. What assumption must be true for this to apply?
→ No external forces acting (closed system).
Explain the difference between Impulse and Force of Impact
Force of Impact is how hard two objects collide in a short amount of time while Impulse is how hard two objects collide in a short amount of time
A 75 kg Hockey puck is pushed with 300 Newtons across frictionless ice.
Step 1: Find acceleration
→ a = 4 m/s²
A 10 kg object accelerates at 5 m/s². A 20 kg object accelerates at 5 m/s². What is the difference between the forces?
→ The 20 kg object requires twice the force (100 N vs 50 N).
Two cars collide. One experiences a large force over a short time, the other a smaller force over a longer time. Which likely experiences greater injury risk and why?
→ Large force over short time — greater impact force.
What is... The mass or velocity of an object can increase or decrease using the equation P=mv. However, due to the law of conservation of momentum (MV + mv = MV + mv)
If a graph shows a curved upward line where force increases faster as mass increases, which type of pattern would that represent?
→ Quadratic
A 60 kg person on a 15 kg sled is pushed with 300 N while friction force is 100 N opposing motion.
Step 1: Find net force
Step 2: Find acceleration
→ Net force = 200 N
→ Acceleration ≈ 2.67 m/s²