Answer:
d= 10.45
Explanation:
First, let's see what Bolt's speed was on his record-breaking sprint. He ran 100\,\,\text{m}100m100, start text, m, end text in 9.58\,\,\text{s}9.58s9, point, 58, start text, s, end text, which is
\dfrac{\blue{100 \,\text{meters}}}{\pink{9.58\,\text{seconds}}}=10.44\,\text{m}/\text{sec}
9.58seconds
100meters
=10.44m/secstart fraction, start color #6495ed, 100, start text, m, e, t, e, r, s, end text, end color #6495ed, divided by, start color #ff00af, 9, point, 58, start text, s, e, c, o, n, d, s, end text, end color #ff00af, end fraction, equals, 10, point, 44, start text, m, end text, slash, start text, s, e, c, end text
to two decimal places. We assume this is Bolt's speed for the duration of his sprint. How does this compare with the speeds represented by the answers?
First, let's consider d=10t\,d=10td, equals, 10, t. If \,t=\red1t=1t, equals, start color #df0030, 1, end color #df0030 second, then d=10(\red1)d=10(1)d, equals, 10, left parenthesis, start color #df0030, 1, end color #df0030, right parenthesis meters, so the speed represented is 10\,\, \text{m/s}10m/s10, start text, m, slash, s, end text. This is less than Bolt's speed.
Which of the remaining answer choices represent a speed that is greater than Bolt's?
The correct answer must have a speed that is greater than 10.4410.4410, point, 44. The only choice that represents a greater speed is d=10.45td=10.45td, equals, 10, point, 45, t. In this case, if t=\red1t=1t, equals, start color #df0030, 1, end color #df0030 second, then d=10.45(\red1)=10.45d=10.45(1)=10.45d, equals, 10, point, 45, left parenthesis, start color #df0030, 1, end color #df0030, right parenthesis, equals, 10, point, 45 meters. The speed is 10.45\,\,\text{m}/\text{s}10.45m/s10, point, 45, start text, m, end text, slash, start text, s, end text.
d=10.45\,td=10.45td, equals, 10, point, 45, t represents a speed that is greater than Bolt's.