Solution to Test Paper 2

From Mechanics

(Difference between revisions)
Jump to: navigation, search
Line 165: Line 165:
|-
|-
| 3 (a)
| 3 (a)
-
| 2
+
| <math>R=20\times 9\textrm{.}8=196</math> N
-
| 3
+
|M1
-
| 4
+
 
-
| 5
+
A1
 +
 
 +
| (2 marks)
 +
| M1: Use of <math>R=mg</math>
 +
 
 +
A1: Correct <math>R</math>.
 +
 
|-
|-
| 3 (b)
| 3 (b)
-
| 2
+
| <math>F=0\textrm{.}4\times 196=78\textrm{.}4</math>
-
| 3
+
| M1
-
| 4
+
 
-
| 5
+
A1
 +
| (2 Marks)
 +
| M1: Use of <math>F=\mu R</math>
 +
 
 +
A1: Correct <math>F</math>.
 +
 
|-
|-

Revision as of 15:35, 19 January 2011

Solutions
1 (a) \displaystyle \begin{align}

& 44 \ \textrm{.}1=\frac{1}{2}\times 9 \ \ 8{{t}^{2}} \\ & t=\sqrt{\frac{44 \textrm{.}1}{4 \textrm{.}9}}=3\text{ s} \\ \end{align}

OR

\displaystyle \begin{align} & s=\frac{1}{2}\times 9 \textrm{.}8\times {{3}^{2}}=44 \textrm{.}1 \\ & \text{AG} \\ & \therefore \text{Hits ground after 3 seconds} \\ \end{align}



M1

A1

A1


(M1)

(A1)

(A1)


(3 marks) M1: Use of constant acceleration

equation with \displaystyle v=0

A1: Correct equation

A1: Correct \displaystyle s


1 (b) \displaystyle \begin{align}

& {{v}^{2}}={{0}^{2}}+2\times 9 \textrm{.}8\times 44 \textrm{.}1 \\ & v=\sqrt{864 \textrm{.}36}=29 \ \textrm{.}4\text{ m}{{\text{s}}^{-1}} \\ \end{align}

OR

\displaystyle \begin{align} & v=0+9 \textrm{.}8\times 3 \\ & v=29 \textrm{.}4 \text{ m}{{\text{s}}^{-1}} \\ \end{align}


M1

A1

A1


(3 marks)


M1: Use of constant acceleration equation with \displaystyle v=0

A1: Correct equation.

A1: Correct \displaystyle v.


1 (c) Air resistance would slow the ball down. B1 (1 mark) B1: Sensible statement about air resistance.
(7 marks)
2 (a) Image:test2ans2.gif B1 (1 mark) B1: Correct horizontal forces.

Ignore any vertical forces.


2 (b) \displaystyle P = 900 \text{N} B1 (1 mark) B1: Correct value for \displaystyle P.
2 (c) \displaystyle \begin{align}

& P-900=2000\times 1\textrm{.}2 \\ & P=2400+900=3300 \text{N} \\ \end{align}

M1

A1

A1

(1 mark) M1: Three term equation of motion

A1: Correct equation

A1: Correct \displaystyle P.


2 (d) \displaystyle \begin{align}

& 800-900=2000a \\ & a=\frac{-100}{2000}=-0\textrm{.}05 \text{ m}{{\text{s}}^{-2}} \\ \end{align}

Car is slowing down


M1

A1

A1

A1

(4 marks) M1: Three term equation of motion

A1: Correct equation

A1: Correct \displaystyle a

A1: Correct statement


(9 marks)
3 (a) \displaystyle R=20\times 9\textrm{.}8=196 N M1

A1

(2 marks) M1: Use of \displaystyle R=mg

A1: Correct \displaystyle R.


3 (b) \displaystyle F=0\textrm{.}4\times 196=78\textrm{.}4 M1

A1

(2 Marks) M1: Use of \displaystyle F=\mu R

A1: Correct \displaystyle F.


3 (c) 2 3 4 5
1 2 3 4 5
4 (a) 2 3 4 5
4 (b) 2 3 4 5
4 (c) 2 3 4 5
1 2 3 4 5
5 (a) 2 3 4 5
5 (b) 2 3 4 5
5 (c) 2 3 4 5


Retrieved from "http://wiki.math.se/wikis/2009/bridgecoursemechanics/index.php/Solution_to_Test_Paper_2"