physics

• Power (P) = energy transfer rate / time taken
• Work done = force x distance moved in same direction
• The second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
• The third law of motion states that for every action, there is an equal and opposite reaction. This means that whenever an object exerts a force on another object, the second object exerts an equal and opposite force on the first object.
• Energy is transferred at the same rate as power.
• Average power can be calculated by dividing total energy transferred by time taken.
• The unit of power is watts, where one joule per second equals one watt.
• Energy is the ability to do work or cause change.
• Kinetic energy is the energy an object has due to its motion, while potential energy is stored energy that can be converted into kinetic energy when released.
• Force = mass x acceleration
• Newton's first law states that if there are no resultant forces acting on an object, then the velocity will remain constant or be zero.
• Average speed = total distance travelled / total time taken
• Acceleration is the change in velocity per unit time.
• average speed is equal to total distance covered divided by total time taken
• average velocity is equal to total displacement divided by total time taken
• rate of change of speed is equal to final speed subtract initial speed divided by time taken
• rate of change of speed is measured in m/s2
• If rate of change of speed is constant, average speed can be calculated as : initial speed add final speed divided by 2
• average velocity = initial velocity add final velocity divided by time taken
• acceleration can be calculated as change in velocity divided by time taken
• acceleration = v-u divided by t
• if acceleration is constant, average velocity = initial velocity + final velocity divided by 2
• force = mass x acceleration
• weight is measured in newtons
• mass is measured in kg
• weight = mass x (acceleration due to) gravity
• hooke's law - extension = extended length - natural length
• force = spring constant x extension
• pressure = force divided by area
• N/m2 = Pascal (Pa)
• moment = force x perpendicular distance
• F1 x D1 = F2 x D2
• density = mass divided by volume
• efficiency = useful energy input divided by energy input (no units needed as its a ratio)
• work done = force x distance (moved in direction of force)
• power = work done divided by time taken or p = w divided by t
• power is measured in joules per second (J/s) or watts (W)
• work is measured in joules (J)
• time is measured in seconds (s)
• Power can also be described as rate of change of energy transferred.