By: Danielle Chandler

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Physics One on One

• By Danielle Chandler
• Jonathan Daniels
• Brian

2
Question

• A boy wishes to row across a river in the
  shortest possible time. He can row at 2 m/s in
  still water and the river is flowing at 1 m/s. at
  what angle O should he point the bow (front) of
  his boat?

3
Answer Selection

• A) 30
• B) 45
• C) 60
• D) 63
• E) 90

4
Working it Out

• Tan ? ½
• ? Tan?¹ ½

5
The Final Answer is

• C) 60

6
Question

• A projectile is fired over level ground with an
  initial velocity that has a vertical component of
  20 m/s and a horizontal component of 30 m/s.
  Using g10 m/s², the distance from launching to
  landing point is

7
Answer Selection

• A) 40 m
• B) 60 m
• C) 80 m
• D) 120 m
• E) 180 m

8
Working it Out

• 30 m/s x 4
• 120
• Answer
• D) 120 m

• Vv at
• 0 20 10t
• 20 10t
• T 2
• T 2 x 2 4

9
Question

• A boy on the edge of a vertical cliff 20 m high
  throws a stone horizontally outwards with a speed
  of 20 m/s. It strikes the ground at what
  horizontal distance from the foot of the cliff?
  Use g 10 m/s²?

10
Answer Selection

• A) 50 m
• B) 40 m
• C) 10 m
• D) 25 m
• E) 120 m

11
Working it Out

• 0 20 0t - 5(t)²
• -20 -5t²
• 4 t²
• T 2
• 20 m/s (2)
• 40 m

• Answer
• B) 40 m

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The End