Chapter 10 - Forces and Motion Flashcards
Newton’s First Law
✯ Newton’s first law states that every object will remain at rest or in uniform motion in a straight line unless acted upon by another force.
Newton’s Second Law
F = M x A
F = Force (Newtons)
M = Mass (Kg)
A – Acceleration
Newton’s Third Law
✯ Newton’s third law states that for every action force in nature, there is an equal and opposite reaction.
What must the object’s force be equal to in equilibrium?
✯ If a particle is in equilibrium, then F = 0
What is the formula for weight?
✯ The weight W is defined as W = mg
m – Mass
g – acceleration due to gravity.
g – 9.8
Explain why an object moving at a constant speed in a circular path must have a resultant force acting on it.
✯ Velocity has direction whereas speed does not. If velocity changes therefore, there is a resultant force acting upon the object.
What assumptions do we make for taught and slack strings?
✯ When the string is taut, initial velocity (u) and final velocity (v) are normal.
✯ However, when the string changes and becomes slack, the initial velocity (u) and final velocity (v) switch.
What happens when the string goes from slack back to being taught again?
✯ When our string goes from slack back to being taut again it takes a further t seconds and thus our t for time is doubled.
What do we assume occurs in the scenario that a particle in a pulley hits the ground?
✯ When a particle in a Pulley hits the ground, the other particle behaves like a particle moving freely under gravity, so acceleration is 9.8 ms^2.
If a pulley is at rest, what is the force exerted at the pulley?
If at rest, F = 2T.