Hiiii. Please help me i want to know the answer to question b and c. Could you please explain and give answer Thanksss!!!

Guest May 11, 2019

#1**+3 **

b) It starts at 0 km/hr at 9:00 and smoothly accelerates until it is moving at 50 km/hr at 9:15; this means that its average speed is 25 km/hr for 1/4 hour; thus, the distance travelled is (25 km/hr ) x (1/4 hr) = 6.25 km.

From 9:15 until 9:45, it travels at the constant speed of 50 km/hr for 1/2 hr; thus, the distance travelled is (50 km/hr) x (1/2 hr) = 25 km.

At 9:45, it smoothly accelerates until its speed is 100 km/hr at 10:00. Thus, its average speed is 75 km/hr and the distance travelled is ( 75 km/hr) x (1/4 hr) = 18.75 km.

From 10:00 until10:30, it travels at the constant speed of 100 km/hr; thus, the distance travelled is (100 km/hr) x (1/2 hr) = 50 km.

From 10:30 until 11:00, it smoothly decelerates, giving an average speed of 50 km/hr for 1/2 hour and a distance of (50 km/hr) x (1/2 hr) = 25 km.

The total distance is: 6.25 km + 25 km + 18.75 km + 50 km + 25 km = 125 km.

c) The average speed = (total distance ) / (total time) = (125 km) / (2 hr) = 62.5 km/hr

geno3141 May 11, 2019

#1**+3 **

Best Answer

b) It starts at 0 km/hr at 9:00 and smoothly accelerates until it is moving at 50 km/hr at 9:15; this means that its average speed is 25 km/hr for 1/4 hour; thus, the distance travelled is (25 km/hr ) x (1/4 hr) = 6.25 km.

From 9:15 until 9:45, it travels at the constant speed of 50 km/hr for 1/2 hr; thus, the distance travelled is (50 km/hr) x (1/2 hr) = 25 km.

At 9:45, it smoothly accelerates until its speed is 100 km/hr at 10:00. Thus, its average speed is 75 km/hr and the distance travelled is ( 75 km/hr) x (1/4 hr) = 18.75 km.

From 10:00 until10:30, it travels at the constant speed of 100 km/hr; thus, the distance travelled is (100 km/hr) x (1/2 hr) = 50 km.

From 10:30 until 11:00, it smoothly decelerates, giving an average speed of 50 km/hr for 1/2 hour and a distance of (50 km/hr) x (1/2 hr) = 25 km.

The total distance is: 6.25 km + 25 km + 18.75 km + 50 km + 25 km = 125 km.

c) The average speed = (total distance ) / (total time) = (125 km) / (2 hr) = 62.5 km/hr

geno3141 May 11, 2019

#5**+2 **

Also, there are 100 squares underneath the blue line, and each square = 5/4 km

100 * 5/4 km = 125 km

hectictar May 11, 2019

#7**+1 **

One question, hectictar......as I don't know much about these kinds of graphs.....how did you determine that each square is (5/4)km ???

CPhill
May 11, 2019