Answer:
Step-by-step explanation: Speed is distance an object travelled per unit time.
It is represented by letter v and can assume various units.
1) [tex]v=\frac{distance}{time}=\frac{d}{t}[/tex]
[tex]v=\frac{90}{5}[/tex]
v = 18 miles per hour
Her average speed is 18 mph.
2) Rearraging formula for distance:
d = v.t
d = 70 * 4
d = 280 miles
You would travel 280 miles.
3) [tex]v=\frac{d}{t}[/tex]
[tex]v=\frac{315}{6}[/tex]
v = 52.5 mph
My average speed is 52.5 mph.
4) Rearranging formula to determine time:
[tex]t=\frac{d}{v}[/tex]
[tex]t=\frac{210}{90}[/tex]
t = 2.34 hours
It will take 2 hours and half to arrive in Leeds. So, we will be expected to arrive at 12:04.
5) The unit change but the way of calculating time is the same.
[tex]t=\frac{2000}{4}[/tex]
t = 500 s
or t = 8.34 minutes
It will take, for an athlete to run 2000m, 8.34 minutes.
6) a) All units must match, so for a speed in mph:
45 minutes is 0.75 hours. Total time is 8.75 hours.
[tex]v=\frac{420}{8.75}[/tex]
v = 560 mph
The average speed is 560 mph.
b) [tex]t=\frac{d}{v}[/tex]
[tex]t=\frac{420}{63}[/tex]
t = 6.67 hours
Sam will take 6.67 hours to covered the distance.
