Questions I dropped marks on

Question 1

explain why the natural frequency of the damper system must be similar to the natural frequency of the oscilator [2]

Answer 1

maximum energy transferred to the dampin system (maximum energy is taken out of the system)

when the damping system is driven similar to the natural frequency of the system

Question 2

two stars of equal mass orbit a common centre of mass
explain why the stars must be diametrically opposite [2]

Answer 2

centripetal force provided by the gravitational force

centripetal force is a along the line joining the two stars therefore must be

Question 3

in a binary system (two stars obiting a CoM) explain why the smaller star travels quicker [2]

Answer 3

they have the same time period

V = (2pi/T)(r)

Question 4

card enters the light gate at an angle explain the affect that would have on the velocity calculated

Answer 4

Card enters at an angle so has to travel less than the distance used in calculation
and because of speed = distance/time so velocity calculated is greater

Question 5

explain how stopping distance for a truck may differ from the stopping distance for a car [4]

Answer 5

thinking distance may be longer
because their more tired (stupid answer for stupid OCR)

breaking distance for truck may be longer
as its more massive

Question 6

water took longer to boil in the kettle than your answer to C
explain why part C is an underestimateand suggest two ways that you can make this less of an underestimate

previous Q was calculate time to boil with certain power input

Answer 6

thermal energy is lost to the surroundings

Lagging the kettle

Cover to prevent evaporation

lagging -coating a material in a another material like steel

if confused on the cover/lid section look at one note if confused (thermal crash course)

Question 7

suggest and explain two ways the crane can be modified to improve ite efficiency

Answer 7

reduce heat loss through friction in movinb parts. i.e oil, bearings

use a stiffer/stronger cable to reduce energy loss through stretching

Question 8

brownian motion demostrated by motion of smoke particles suspended in air under a microscope
state the observation and conclusion associated with this brownian motion

Answer 8

smoke particles show random motion
because of collisions with air molecules