Is a branch of science that deals with the properties, behavior and interaction between matter and energy. PHSYICS. Subdivisions of Physics. Classical Mechanics : study of motions based on Newton’s laws of mechanics
Is a branch of science that deals with the properties, behavior and interaction between matter and energy
Length: locates position of a point in space
Time: succession of events
Mass: amount of matter in a body
What is the volume of a cylinder which has a diameter of 6 cm and a height of 5 cm?
Formula: V = ∏r2h
Answer: 45 ∏ cm3
What is the density of a 40 ft x 25 ft x 10 ft rectangular prism if it has a mass of 50000 grams?
D = mass/volume
Answer: 5 g/ft3
Answer: 3450 ml
20 seconds = ? hours
10 m/s = ? km/h
10 cm3 = ? m3
i.e. Length, mass, time, speed, energy, temperature, etc.
VECTORSQuantities described by both magnitude and direction.
i.e. Position, force, displacement, velocity, acceleration, torque, momentum ,etc.
A. Four primary directions
B. Cartesian Plane
Displacement = final position – initial position
Average speed = distance travelled/elapsed time
Average velocity = ∆ in position/elapsed time
A = (final velocity – initial velocity)/ elapsed time
A = ∆V/ ∆T
s = d/t = 330 km/11hrs = 30 km/hr
A cart accelerates from 88 m/s to 121 m/s in 11 s. What is its acceleration?
A = ∆v/ ∆t = (121-88)/11 = 3 m/s2
What is the velocity after 20 s? What is the distance travelled by the car?
FREE FALL – uniformly accelerated motion under the sole influence of gravity.
A = 9.8 m/s2 downward
Downward gravitational acceleration is indicatedby making acceleration negative.
Inertia: property of matter that resists changes in motion
Mechanical Equilibrium: achieved when sum of all forces acting upon an object is zero.
A = force / mass
Force: push or pull done on an object that changes its state of motion
FREE BODY DIAGRAMS
SHOW RELATIVE MAGNITUDE AND DIRECTION OF ALL FORCES ACTING UPON AN OBJECT IN A GIVEN SITUATION.
Horizontal (x-axis) component of motion
X = Vicosθt
Vertical (y-axis) component of motion
Y = Visinθt + 1/2gt2
- velocity changes in direction yet the magnitude remains constant, thus motion is accelerate
- direction of acceleration is inward due to centripetal force
Torque = FI
*where F = force applied perpendicularly; I = distance of applied force from fulcrum/axis
Linear Momentum and Collisions
P = mass x velocity = mv
*where P = momentum
MECHANICAL ENERGY: energy possessed by a body due to its position (Potential energy) or motion (Kinetic energy)
ME = PE + KE
PE = mgh
KE = 1/2mv2
Work = Force x Distance
Power = Work / Time
*unit for power is the Joule/second or simply watt.
V = IR
I – Current; unit: ampere (A)
V – Voltage; unit: volt (V)
R – Resistance; unit: ohm (Ω)
Law of Reflection
Angle of incidence = Angle of reflection
Refraction: change in direction of a wave due to a change in its speed when passing through a different medium
Law of Refraction
n1sinθ1 = n2sinθ2
Image characteristics: virtual, upright, same distance from the mirror as the object’s distance, same size as the object