t2 science Flashcards
(19 cards)
What is Newton’s First Law of Motion?
An object will stay at rest or move at a constant speed in a straight line unless acted on by an unbalanced force. (Law of Inertia)
How does Newton’s First Law apply to stationary and moving objects?
A stationary object stays still unless a force moves it.
A moving object keeps moving at the same speed and direction unless a force slows it down or changes its direction.
What is a free body diagram (FBD)
A diagram that shows all the forces acting on an object using arrows.
What are common forces shown in a free body diagram?
Gravity/Weight (down)
Normal force (up)
Friction (opposite motion)
Applied force (push/pull)
What is Newton’s Third Law of Motion?
For every action, there is an equal and opposite reaction.
How can you predict outcomes using Newton’s Third Law?
If object A pushes on object B, object B will push back with the same force in the opposite direction (e.g. jumping off a boat causes the boat to move back).
How does Newton’s Third Law apply to gravity between two objects?
Both objects pull on each other with equal and opposite gravitational forces (e.g. Earth pulls on the Moon, and the Moon pulls back on Earth with equal force).
How does Newton’s Third Law apply to forces between objects?
Any force applied by one object to another causes an equal and opposite force in return (e.g. your foot pushes a ball, the ball pushes back on your foot).
What is Newton’s Second Law of Motion?
Force = Mass × Acceleration
How do you calculate force using Newton’s Second Law?
Multiply the object’s mass (kg) by its acceleration (m/s²).
Example: F = 5 kg × 2 m/s² = 10 N
How do you calculate mass or acceleration using Newton’s Second Law?
Mass = Force ÷ Acceleration
Acceleration = Force ÷ Mass
How do you read and interpret a velocity-time graph?
Flat line = constant speed
Sloped line = acceleration/deceleration
Area under the graph = displacement
How do you read and interpret a displacement-time graph?
Straight diagonal line = constant speed
Flat line = no movement
Curved line = changing speed (acceleration)
What is the Big Bang Theory?
The theory that the universe began from a very hot, dense point about 13.8 billion years ago and has been expanding ever since.
What is redshift, and how does it support the Big Bang Theory?
Redshift is when light from distant galaxies stretches as they move away. This shows the universe is expanding, supporting the idea of the Big Bang.
What is cosmic microwave background radiation (CMBR)?
Faint heat energy left over from the early universe. It’s found everywhere in space and supports the Big Bang Theory.
What is the significance of the hydrogen-to-helium ratio in the Big Bang Theory?
The universe is about 75% hydrogen and 25% helium — a ratio predicted by Big Bang models, showing elements formed in the early universe.
What is the Big Bang theory?
The Big Bang Theory is the scientific explanation for how the universe began. It states that the universe started as a very hot, dense point about 13.8 billion years ago and has been expanding ever since. This expansion means galaxies are moving away from each other, and the universe is getting bigger over time.
Explain how Newton’s Laws of Motion apply when kicking a soccer ball.
Newton’s First Law (Inertia):
The soccer ball stays still until a force (your foot) acts on it. Once kicked, it keeps moving in the same direction unless friction or another force stops it.
Newton’s Second Law (F = m × a):
The harder you kick the ball (more force), the faster it accelerates. A heavier ball requires more force to accelerate at the same rate as a lighter one.
Newton’s Third Law (Action–Reaction):
When your foot pushes on the ball, the ball pushes back on your foot with an equal and opposite force. This is why you feel the impact when you kick it.
