Required practicals

Question 1

What’s the equipment for the required practical, about acceleration ? [not involving a light gate]🧵

Answer 1

• a trolley, attached to a piece of string [looped around a pulley]
• and, the other end of the string being attached to a 100g mass.
• and, and a stopwatch

Question 2

What will the weight of 100g mass do, in the required practical about acceleration? 🧵

Answer 2

• the weight of the [100g] mass, will provide the force acting on the trolley

Question 3

What’s the required practical, about acceleration ? [that doesn’t use a light gate] 🧵

Answer 3

1) draw chalk lines at equal intervals [e.g- every 10cm], on the desk.

2) and, hold the trolley at the starting point; when you are ready, let go of the car

3) ; because there’s a resultant force acting through the string, the trolley will accelerate along the bench

4) also record the time, that the car passes each distance marker

5) then repeat the expirement several times; decrease the last, on the end of the string. [e.g- 80g, 60g, 40g and 20g]- meaning the weight, will decrease each time.

Question 4

What promblems are there, about acceleration practical ? [that doesn’t use a light gate] 🧵

Answer 4

• if the car is moving rapidly, it will be difficult to record an accurate time.
• therefore, you could record the experiment on a mobile phone, and then play the video back- to record the time accurately.

Question 5

What happened, if we take away some of the mass from the string ? 🧵

Answer 5

• if we take away some of the mass from the string, we then have to transfer the mass onto the trolley.
• This is because, the overall mass has to be kept same

Question 6

What’s the object or system, in the acceleration required practical ? 🧵

Answer 6

• the object/system is actually: the trolley, string and the mass on the end of the string.
• This is because, they’re all attached to each other, and are therefore counted as the object/system]

Question 7

What are the dependent, independent and control variables in the acceleration required practical ?🧵

Answer 7

• dependent variable- the trolley’s acceleration
• independent variable- the pulling force acting on the object
• control variable- the mass of the system and, the same distance from where the trolley was pushed

Question 8

In the acceleration required practical, what should we expect to see ? 🧵

Answer 8

• we should expect to find, that the acceleration of the toy car, is proportional to the mass on the other end of the string.
• This is because Newton’s second law of motion, tells us that the acceleration of an object, is proportional to the force applied.

Question 9

What’s the control variables, in the acceleration required practical ? 🧵

Answer 9

• control variable- the mass of the system and, the same distance from where the trolley was pushed

Question 10

What’s the dependent variable, in the acceleration required practical ? 🧵

Answer 10

• dependent variable- the trolley’s acceleration

Question 11

What’s the independent variable, in the acceleration required practical ? 🧵

Answer 11

• independent variable- the pulling force acting on the object

Question 12

What’s the required practical about Hooke’s law, to investigate the relationship between force and extension of a spring ?

Answer 12

1) Attach a wooden spring, that will act as a pointer to the base of the spring; ensure that it isn’t angled [paralleled to the work bench] and perpendicular to the metre ruler.

2) Align the top of the ruler with the top of the spring, and measure the initial length of the spring without any weight [force] attached.

3) Add a 10g mass to the base of the spring and record the length of the spring.

4) Repeat and continue to add masses, ensuring that the spring doesn’t oscillate after each weight has been added.

5) then calculate the extension of the spring for each mass by: subtracting the initial length of the spring, from each different length of the spring.

6) convert all masses to weights using the equation: Weight (N) = mass (kg) x 9.81 (N/kg)

7) and then plot the graph of force (y-axis) against extension (x-axis)- calculate the gradient,

Question 13

What is the difference between a linear relationship 🆚 non-linear relationship ?

Answer 13

• a linear relationship, means there is a straight line graph
• ; a non-linear relationship, means there isn’t a straight line graph

Question 14

In the Hooke’s law practical, what happens if the spring obeys Hooke’s law ?

Answer 14

• if the spring obeys Hooke’s Law, the graph of force against extension will be linear, and it will pass through the origin.
• this means, the gradient will be equal to 1 / k, where k is the Spring Constant measured in N/m.