Newtons Laws 1
This is required to overcome an object’s inertia.
unbalanced force?
This is a measure of the change in the velocity of a moving object. (speeding up or slowing down)
acceleration?
One object pushing on another will always receive a push in return. True or false.
True
Which object will hit the ground in a vacuum with the most force; feather or bowling ball?
bowling ball
A student applies a force to accelerate a 20 kg grocery cart at a rate of 2.5 m/s^2. What is the net force acting on the cart?
Shopping Cart:
Formula: F=ma
Calculation: F=20 kg×2.5 m/s^2
Answer: 50 N
Newton’s Second Law can be summarized using this equation.
force = mass x acceleration?
The unit for force
What is the Newton?
If forces are cancelled out, they are Balanced or Unbalanced forces.
Balanced
Forces come in _____
Pairs
During a soccer match, a player kicks a 0.45 kg ball with a net force of 9 N. What is the acceleration of the soccer ball as it leaves the player's foot?
Soccer Kick:
Formula: a=F/M
Calculation: a=9N/0.45kg
Answer: 20 m/s^2
The tendency of an object to resist a change in its motion. This is the definition of ________
inertia
When mass increases, what happens to inertia?
increases?
A car and a train are going the same speed. The car is easier to stop because of this.
less mass and less inertia
Which law? F=mxa
Newton's 2nd law
A mechanical thruster on a space rover produces 150 N of net force, causing the rover to accelerate at 0.5 m/s^2 across the Martian surface. What is the total mass of the space rover?
Space Rover:
Formula: m=F/A
Calculation: m=150N/0.5m/s^2
Answer: 300 kg
What causes a ball that has been kicked across the ground to stop?
Friction
Objects with more mass are ______ to set in motion.
harder
As an objects mass increases, what happens to its momentum?
Increases
In a vacuum chamber, what is the only force acting on objects? (name of force and number needed)
Gravity - 9.8 meters per second squared
Two kids push a heavy sled across snow. Together, they exert a forward pushing force of 80 N. The snow exerts a friction force of 20 N pushing backward against the sled. If the sled has a mass of 30 kg, what is its acceleration?
Net Force: Forward Force−Friction=80 N−20 N=60 N
Formula: a=F/M
Calculation: a=60N/30kg
Answer: 2 m/s2
According to Newton’s Second Law, if the force increased but the mass remained the same, what happens to acceleration?
The objects acceleration increased.
A bowling ball and a feather will fall at the same speed and acceleration in a vacuum because there is no...
air resistance, drag, or fluid friction.
A car is moving north at a speed of 60km/h with 1000N of force and is also experiencing 1200N of force in the south direction.
1. Is the car accelerating, staying still or decelerating?
2. Name one force that's acting in the south direction?
1. Decelerating.
2. Fluid friction (air resistance), rolling friction (road and tyres), sliding friction (brake pads).
Runner A has a mass of 50 kg and exerts a ground force of 200 N. Runner B has a mass of 60 kg and exerts a ground force of 210 N. Which runner has a greater initial acceleration? Show the math for both runners to support your answer.
Runner A Acceleration: a= 200N/50kg =4 m/s2
Runner B Acceleration: a=210N/60kg =3.5 m/s2
Answer: Runner A has the greater initial acceleration (4 m/s2 vs. 3.5 m/s2).