Preliminary HSC Physics Revision

What is the formula for the velocity of a wave?

• v = f λ
• c=fl
• v=fA
• v=ut+1/2at^2

Two cars are driving in the same direction on a highway. From the Perspective of Car A, Car B is moving 30 km/h faster than it. A speed camera displays the speed of Car A as 100km/h. If the speed limit is 120 km/h on the highway, will Car B be speeding.

• Speed of Car A relative to ground = 100km/h Speed of Car B relative to the ground = 100km/h + 30 km/h = 130 km/h 130 km/h > 120 km/h Therefore, Car B will be speeding by 10 km/h.
• Speed of Car A relative to ground = 100km/h Speed of Car B relative to the ground = 100km/h + 30 km/h = 130 km/h 130 km/h < 120 km/h Therefore, Car B will be under the limit by 10 km/h.

As distance increases, the loudness of a sound…

• Decreases according to the inverse square law
• Increases according to the inverse square law
• Decreases according to the recirical distance law

What is the difference between distance and displacement

• Distance is the length without direction while Displacement is the position relative to the starting point
• Distance is the position relative to the starting point while Displacement is the length without direction
• There is no difference

Loudness is determined by the following property of sound waves:

• Amplitude
• Frequency
• Wavelength

What is newton's first law?

• Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
• The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
• For every action (force) in nature there is an equal and opposite reaction

A plane at 300km/h N, there is a wind of 70km/h from the east, what is the resultant vector of the planes velocity

• Pythagoras, a^2+b^2=c^2 300^2+70^2=c^2 Square Root = c =308.1km/h
• Draw to scale Measure with Rule AKA "I'm an engineer and like to draw pictures"
• Pythagoras, a^2+b^2=c^2 300^2+70^2=c^2 =94 925km/h

What does a dipole structure consist of”

• Connected positive and negative pole, and electrical field
• Disconnected positive and negative pole
• Disconneted positive and negative pole and a magnetic field

Are sound waves transverse or longitudinal?

• Longitudinal
• Transverse
• Neither, they are electromagnetic

When a wave source and observer are getting closer to each other, wave crests _____ meaning the observed frequency ______

• Bunch together, increases
• Spread apart, decreases
• Spread apart, increases