Question

In the Netherlands, there is an annual ice-skating race called the "Tour of the Eleven Towns." The total distar.rce of the course is 2.00 x 102 krn, and the record time for covering it is 5 h,40 min, 37 s. a. Calculate the average speed of the record race. b. If the first half of the distance is covered by a skater moving with a speed o[ 1.05v, where y is the average speed found in (a), how long will it take to skate the first halft Express your answer in hours and minutes.

Answer 1

a) The average speed of the record race is 35.2 km/h

b) The time it will take to cover the first half is 2h 42 min

Step-by-step explanation:

a) The average speed of the record race is calculated dividing the total distance over time:

v = distance/ time

So let´s write the time in hours:

if 60 s is 1 min, then 37 s will be (37 s · 1 min/60 s) 0.62 min.

If 60 min is 1 h, then 40.62 min will be (40.62 min · 1 h/60 min) 0.68 h

Then, the record time is 5.68 h

The average speed will be:

v = 2.00 × 10² km / 5.68 h = 35.2 km/h

b) Now we have the speed and the distance and have to find the time it will take the skater to cover that distance:

The speed will be:

v = 1.05v = 1.05 · 35.2 km/h = 37.0 km/h

The distance will be:

2.00 × 10² km /2 = 1.00 × 10² km

Then:

v = distance/ time

time = distance /v = 1.00 × 10² km / 37.0 km/h = 2.70 h

If 1 h is 60 min, 0.70 h will be (0.70 h · 60 min/h) 42 min.

The time it will take to cover the first half is 2h 42 min