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PHYSICS, M1 EQ-Bank 11

 A plane is travelling at 315 ms\(^{-1}\) north when it passes through a dense cloud and slows down to a velocity of 265 ms\(^{-1}\) for safety precautions.

The plane did not change direction and travelled 2.5 km while it was slowing down.

Using north as the positive direction for all calculations, determine:

  1. the change in velocity of the plane.   (1 mark)

  2. the plane's acceleration.   (2 marks)

  3. the time over which the plane slowed down.   (2 marks)

Show Answers Only

a.   \(\text{50 ms}^{-1}\ \text{south}\)

b.   \(\text{5.8 ms}^{-2}\ \text{south}\) 

c.   \(\text{8.62 s}\)

Show Worked Solution
a.     \(\Delta v\) \(=v-u\)
    \(=265-315\)
    \(=-50\ \text{ms}^{-1}\)
    \(=50\ \text{ms}^{-1}\ \text{south}\)

 

b.    Using  \(v^2=u^2 +2as\)  (time is not given):

\(a\) \(=\dfrac{v^2-u^2}{2s}\)  
  \(=\dfrac{(265)^2-(315)^2}{2 \times 2500}\)  
  \(=-5.8\ \text{ms}^{-2}\)  
  \(=5.8\ \text{ms}^{-2}\) to the south.  

 

c.    Using  \(v=u+at\):

\(t\) \(=\dfrac{v-u}{a}\)  
  \(=\dfrac{265-315}{-5.8}\)  
  \(=8.62\ \text{s}\)  

PHYSICS, M1 EQ-Bank 8

A truck travelling in a straight line with a speed of 60 ms\(^{-1}\) slows down and comes to rest over a period of 20 seconds.

  1. Calculate the change in velocity of the truck.   (2 marks)

  2. Determine the average acceleration of the truck across the 20 seconds.   (2 marks)

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a.   \(-60\ \text{ms}^{-1}\)

b.   \(-3\ \text{ms}^{-2}\)

Show Worked Solution
a.     \(\Delta v\) \(=v-u\)
    \(=0-60\)
    \(=-60\ \text{ms}^{-1}\)

 

b.     \(a\) \(=\dfrac{v-u}{t}\)
    \(=\dfrac{-60}{20}\)
    \(=-3\ \text{ms}^{-2}\)

PHYSICS, M1 2013 HSC 4 MC

Students performed an investigation to determine the initial velocity of a projectile.

Which row correctly identifies a hazard of this investigation and a related precaution?
 

  Hazard Safety precaution
A.   flying projectile wearing safety glasses
B.  range of projectile measuring the range with a tape measure
C.  enclosed shoes limiting the range of the projectile
D.  safety glasses flying projectile
Show Only

\(A\)

Show Worked Solution

→ A hazard is a danger and the only danger in the answer options is the flying projectile.

→ Wearing safety glasses will protect students eyes from being hit from the projectile.

\(\Rightarrow A\)