Chapter 2 Answer Key: Average Speed and Velocity

2.1 Average Speed/Velocity

1.  76 km/h².  10

2 m/s

3.  (i)  600 km (ii)  32 h

4.  (i) 0.42 m/s  (ii)  0.12 m/s NW

5.  1.13 km²

2.2 Average Speed /Velocity (Converting Units)

1.  1 m/s = 3.6 km/h – To change m/s to km/h multiply by 3.6 and to change km/h to m/s divide by 3.6

2.  75 m

3.  101 km

4.  30 km

5.  252 km

6.  305 km

2.3 Average Speed and Velocity (similar to 2.2 but these take more time to solve)

1.  3220 km²(≈ 3000 km²)

2.  120 km/h

3.  925 km/h

4.  (i)  240 km   (ii)  96 km/h

5.  Impossible to do

6.  0.57 s

7.  4.0 minutes

8.  1.25 m

2.4 Relative Velocity in One Dimension

1.  704 m

2. (i) 90 km/h(ii) 180 km/h(iii) 142 km/h at 18.4°

    (iv) 17.3°(v) 128 km/h(vi) 1.95 h

3. (i)  6.3 cm(ii) 1800 km (iii)  256 km/h

     (iv) 1.57 h(iv) 2.81 h

2.5.1 Horse Transportation

(i)  7.53 x 108 Horses (753 million horses)

(ii)  6.03 x 108 hectares

2.5.2 The First Measure of the Speed of Light

(i) 2.26 x 108 m/s

(ii) 2.97 x 108 m/s

2.5.3 The Time Delay in Communication between Earth and Mars

(i) 377 s   or   6 min 17 s

(ii) 656 s   or  10 min 57 s

(iii) 2642 s  or  44 min 2 s

2.5.4 The Carrington Event

1.  CME speed is 2.37 x 106 m/s or 8.5 million km/h