Forces and Newton's laws - Topic 8 Flashcards
Concepts of force, Newton's second law, use weight and motion in a straight line under gravity, Newton's third law, addition of forces, and use the F ≤ µR model
Year 1 - Chapter 10.1
What is Newton’s First Law?
Newton’s first law of motion states than an object at rest will stay at rest and that an object moving with constant velocity will continue to move with constant velocity unless an unbalanced forces acts on the object. A resultant force acting on an object will cause the object to accelerate in the same direction as the resultant force.
Year 1 - Chapter 10.3
What is Newton’s Second Law?
It states that the force needed to accelerate a particle is equal to the product of the mass of the particle and the acceleration produced: F = ma.
Year 1 - Chapter 10.5
How do connected particles change the assumptions made in a model?
Connected particles require an equal and opposite reaction between the two particles in the string connecting them - Newton’s Third Law. If object A exerts a force on object B, then object B exerts a force on object A that is equal in magnitude and acts in the opposite direction.
Year 2 - Chapter 5.1
How do you calculate resolving forces?
If a force is applied at an angle to the direction of motion, you can resolve it to find the component of the force that acts in the direction of motion. The component of a force of magnitude F in a certain direction if Fcosθ, where θ is the size of the angle between the force and the direction.
Year 2 - Chapter 5.3
What does the maximum of friction equal to?
Fₘₐₓ = μR,
where μ is the coefficient of friction and R is the normal reaction between the two forces
Year 2 - Chapter 7.1
How should you tackle static particle problems?
- Draw a diagram
- Resolve the forces into horizontal and vertical components or, if the particle is on an inclined plane, into components parallel and perpendicular to the plane
- Set the sum of the components in each direction equal to zero
- Solve the resulting equations to find the unknown force(s)
Year 2 - Chapter 7.3
When is Fₘₐₓ reached?
When the body you are considering is on the point of moving. The body is said to be in limiting equilbrium.
Year 2 - Chapter 7.4
What rotational forces should you consider for a static rigid body in equilibrium?
- The body is stationary
- The resultant force in any direction is zero
- The resultant moment is zero
Year 2 - Chapter 7.5
What does the force of friction equal on an rough, inclined plane?
When a particle is moving along a rough plane, the force of friction is equal to μR, and acts so as to oppose the direction of motion.
