Answer
1 Mile = 1600 m
1Km = 1000 m
1 Year= 365 Days
1Day= 24 hours
1 Hour = 3600 sec
Work Step by Step
28 (a): Solution
55miles/ hour
=> $55 * \frac{1600m}{3600s}$ because 1mile = 1600m and 1 hour = 3600sec
solving we get, 24.44m/sec
28 (b) Solution
40 Km/hour
=> $40 * \frac{1000m}{3600s}$ => 11.11m/sec
28(c) Solution :
1 week
1 week = 7 days = 1*7*24*3600sec
=> 604800Sec
28(d) Solution
Period of Mars
As per Appendix E " Period of Mars is 1.88 years
=> 1.88 * 365 days
=> 1.88*365*24*3600Sec
=> 59287680 Sec
