Kinematics
What is the difference between distance and displacement?
Answer: Distance is the total length of the path traveled, while displacement is the straight line distance from the initial to the final position, considering direction.
State Newton’s first law of motion.
Answer: An object at rest stays at rest, and an object in motion stays in motion at a constant velocity unless acted upon by a net external force.
What is the principle of conservation of energy?
Answer: The principle of conservation of energy states that energy cannot be created or destroyed; it can only be transformed from one form to another.
Define velocity and its relationship to position.
Answer: Velocity is the rate of change of position over time, indicating both speed and direction of motion.
What is a free-body diagram?
Answer: A free-body diagram is a graphical representation showing all the forces acting on an object, used to analyze the forces and their effects.
Write the formula for work done by a constant force.
Answer: The work done (( W )) by a constant force is given by ( W = Fs ), where ( F ) is the force component and ( s ) is the displacement in the direction of the force.
What are the equations of motion for uniformly accelerated motion?
Answer: The three key equations are:
Describe the normal (reaction) force in physics.
Answer: The normal (reaction) force is the component of the contact force acting perpendicular to the surface that supports the weight of an object resting on that surface.
Define kinetic energy and its formula.
Answer: Kinetic energy (( Ek )) is the energy of an object due to its motion, calculated by the formula ( Ek = 1/2 mv2 ), where ( m ) is mass and ( v ) is velocity.
Explain instantaneous and average velocity.
Answer: Average velocity is the total displacement divided by total time, while instantaneous velocity is the velocity of an object at a specific moment in time.
What is the formula for gravitational force?
Answer: The gravitational force (( Fg )) is calculated using the formula ( Fg = mg ), where ( m ) is mass and ( g ) is the acceleration due to gravity.
What is power in terms of work done?
Answer: Power (( P )) is the rate at which work is done or energy is transferred, expressed as ( P = W/t ).
What is projectile motion, and how can it be analyzed?
Answer: Projectile motion is the motion of an object thrown into the air under the influence of gravity, analyzed using horizontal and vertical components of motion.
Explain the concept of impulse and its relation to momentum.
Answer: Impulse (( J )) is the product of the average resultant force (( F )) and the time duration (( delta t )) over which it acts, defined as ( J = F \Delta t ). It equals the change in momentum of the system.
Explain energy efficiency and its formula.
Answer: Energy efficiency measures how much useful energy is obtained from a process compared to the total energy input, calculated as ( efficiency = useful work out/total work in or useful power out/total power in ).