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PHYSICS, M2 2023 VCE 8 MC

At a swimming pool, Sharukh and Sam, shown below, step off the low diving board at the same time. Over the small distance they fall, air resistance may be ignored. Sharukh and Sam have masses of 80 kg and 60 kg respectively.
 

Which one of the following best explains what happens to Sharukh and Sam as they drop straight down into the water?

  1. Sharukh reaches the surface first because she has a larger mass.
  2. The net force on Sharukh is larger than that on Sam, so Sharukh reaches the surface first.
  3. They both reach the surface together because they both experience the same downward force.
  4. They both reach the surface together because they both experience the same downward acceleration.
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\(D\)

Show Worked Solution

→ Both Sharukh and Sam fall under the acceleration of gravity which is 9.8 ms\(^{-2}\).

→ They will fall at the same speed and therefore hit the surface at the same time.

\(\Rightarrow D\)

PHYSICS, M2 2014 HSC 3 MC

A pendulum is used to determine the value of acceleration due to gravity. The length of the pendulum is varied, and the time taken for the same number of oscillations is recorded.

Which of the following could increase the reliability of the results?

  1. Changing the mass of the pendulum
  2. Identifying the independent and dependent variables
  3. Recording all measurements to at least four significant figures
  4. Repeating each measurement several times and recording the average
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\(D\)

Show Worked Solution

→ Reliability of data can be increased by repeating the same experiment numerous times and recording an average from the data as it eliminates random error.

\(\Rightarrow D\)

PHYSICS, M2 2018 HSC 14 MC

A pendulum can be used to determine the acceleration due to gravity using the relationship

\(\displaystyle T=2 \pi \sqrt{\dfrac{l}{g}}\)

where \(T\) is the period and \(l\) is the length of the pendulum.

The acceleration due to gravity on the surface of Mars is less than that on Earth.

Which graph relates the variables for the pendulum correctly for both planets?
 

 
 

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\(C\)

Show Worked Solution

→ Rearranging the equation given  \(\Rightarrow\ \ l=\dfrac{T^2}{4\pi^2} \times g\)

→ Thus \(\ l \propto T^2\).

→ It will be a nonlinear graph between \(l\) and \(T\).

→ As the value of \(g\) for Mars is less than that of Earth, the data line for Mars must be below that of Earth.

\(\Rightarrow C\)
♦ Mean mark 478%.

PHYSICS, M5 2018 HSC 11 MC

During the launch of a space vehicle from Earth, an astronaut feels an increased downward `g` force.

In which of the following situations would a person also feel an increased downward `g` force?
 

 

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`D`

Show Worked Solution

→ A feeling of increased downwards `g` force is a result of upwards acceleration.

→ Options A, B and C all involve zero or downwards acceleration.

`=>D`