Physics ATP

Question 1

explain why measuring the time for 20 oscillations rather than one gives a more accurate value for T

Answer 1

reduces effect of error in starting/ stopping stopwatch

Question 2

state one precaution to ensure reliable temp. of water in beaker

Answer 2

• stirring
• viewing scale perpendicularly
• wait for the mercury to stop rsing

Question 3

how can we tell a relation is not directly proprtional through a graph

Answer 3

the line does not pas through the origin

Question 4

ray diagram inaccuracy

Answer 4

thickness of pins, thickness of mirror, difficulty in aligning pins, protrcator is not precise

Question 5

lens experiment precaution for reliability

Answer 5

• everything placed perpendicular to bench
• lens and object same height
• darkened room
• place metre rule or clamp in position on bench

Question 6

the student stated that it is difficult to place the mass accurately at the 95 cm mark. how could the student overcome this

Answer 6

mark center line of mass and the edge of the ruler

Question 7

describe a method to find the point at which the meter rule is as near to being as balanced as possible

Answer 7

find point which just tips one way and then move rule to find point which tip the other way. balance point is between these where rule tips either way

Question 8

suggest one reason why it is difficult to decide on the best position of the lens to obtain a sharply focused image on the screen

Answer 8

image appears well focused over a small range of lens positions ; not all of the image is focused at the same time

Question 9

before starting the experimen, the student determines the position of the center of the mass of the meter rule, how would you do this

Answer 9

place rule on pivot without the masses and move it until you find the balance point.

Question 10

precautions of pins in ray diagram

Answer 10

place pins 5 cm far apart, thin pins, view bases of pins.

Question 11

suggest a cause for the inaccuracy in timing

Answer 11

human reaction time

Question 12

suggest how you would measure the diameter of the depression made by the hole

Answer 12

ruler, repeat for different diameters around the hole

Question 13

Red had a large what than violet

Answer 13

Wavelength

Question 14

How does an image from from an ultrasound

Answer 14

Reflected from the baby

Question 15

Two current carrying wires are into the page what is the direction of force

Answer 15

Attraction

Question 16

A sample of an C14 is left for a period time which two quantities half during a half life

Answer 16

The number of nuclei and the decay rate

Question 17

What instrument to use when finding the circumference of a golf ball

Answer 17

Tape

Question 18

What place reading does mm acre gauge give?

Answer 18

0.01 mm

Question 19

How to increase range?

Answer 19

Increase diameter

Question 20

Electricity billllz

Answer 20

Calculated through KWHr

• To get time multiply no of weeks with days and hours
• then convert watts into kW (divide by 1000)
• use energy formula E=Vit

Question 21

when the direction of speed velocity changes and your dealing with acceleration what do u do?

Answer 21

you add the values and then divide it by time

Question 22

How to increase range?

Answer 22

Increase diameter

Question 23

Electricity billllz

Answer 23

Calculated through KWHr

• To get time multiply no of weeks with days and hours
• then convert watts into kW (divide by 1000)
• use energy formula E=Vit

Question 24

which energy resource does not have the sun as its origin

Answer 24

geothermal

wind and hydroelectric and coal do!!

Question 25

fusion

Answer 25

energy is emitted