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A student investigates how a spring stretches - OCR Gateway - GCSE Physics - Question 21 - 2020 - Paper 1
Question 21
A student investigates how a spring stretches. She measures the original length of the spring, adds a 2.0 N weight, and then measures the extended length of the spr... show full transcript
Worked Solution & Example Answer:A student investigates how a spring stretches - OCR Gateway - GCSE Physics - Question 21 - 2020 - Paper 1
Step 1
Calculate the spring constant for the spring.
Answer
To calculate the spring constant (
vegin{align*}
k & = rac{F}{e} \
ext{where:}
f & ext{ is the force applied (2.0 N)} \
e & ext{ is the extension (4.0 cm = 0.04 m)}
egin{align*}
k & = rac{2.0 ext{ N}}{0.04 ext{ m}}
& = 50 ext{ N/m}.
ext{Therefore, the spring constant is } 50 ext{ N/m (or } 5.0 ext{ N/cm}).
\end{align*}
This equation calculates how much the spring extends for a known force.
Step 2
Suggest two ways that the student could improve and develop their method to find the spring constant.
Answer
-
Use a greater range of weights: This would allow for more data points, improving the accuracy of the spring constant by reducing the percentage error.
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Conduct repeated trials: By measuring multiple times for the same weight and averaging the results, random errors can be minimized, leading to a more reliable value for the spring constant.
Step 3
Calculate the energy stored in the spring when it is stretched 0.20 m.
Answer
The energy stored in the spring can be calculated using the formula: E = rac{1}{2} k x^2 where:
- is the energy stored,
- is the spring constant (40 N/m),
- is the displacement (0.20 m).
Substituting the values gives: E = rac{1}{2} (40 ext{ N/m}) (0.20 ext{ m})^2 = rac{1}{2} (40) (0.04)