Force, Motion, and Energy Flashcards
What is Newton’s 1st Law of Motion?
“An object in motion will remain in motion and an object at rest will remain at rest unless acted upon by an unbalanced force.” (Inertia)
What is Newton’s 2nd Law of Motion?
“The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to the mass of the object” (acceleration)
What is Newton’s 3rd Law of Motion?
“When object A exerts a force on object B, then object B exerts a force that is equal in magnitude and opposite in direction on object A” (action and reaction)
How does friction affect the motion of an object?
Friction can slow things down and stop stationary things from moving
Describe the energy changes of an object of mass 3 kg as it falls from a height of 5m to the ground level (height 0m).
Gravitational Potential -> Kinetic. Some lost to heat and sound.
Describe the difference between scalar and vector quantities.
Scalar quantity: only has a magnitude (number) (Distance, Speed)
Vector: has a magnitude (number) and direction
(Displacement, Velocity)
Difference between distance and displacement
Distance (how far you’ve travelled)
displacement (how far you are from your starting position)
A motorbike travels 87km in 2 and a half hours. Calculate the average speed of the car in km/hr.
34.8 km/hr
A fish swims 75m in 32 seconds. Calculate the average speed of the fish in m/s.
2.34 m/s
Convert 15 m/s to km/hr.
54 km/h
Convert 110 km/hr to m/s.
30.56 m/s
Calculate the net force needed for 200kg object to accelerate at 3m/s2.
600 N
Calculate the weight of an object (on earth) that has a mass of 70kg.
686 N
Calculate the weight of an object that has a mass of 30kg on the moon (acceleration due to gravity: 1.622m/s2)
48.66 N
State the law of “Conservation of Energy”
The law of conservation of energy states that energy can neither be created nor destroyed - only transferred or transformed.
