A tortoise can run with a speed of 0.11 m/s, and a hare can run 20 times as fast

Question

A tortoise can run with a speed of 0.11 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 3.0 minutes. The tortoise wins by a shell (35 cm). How long does the race take? What is the length of the race? A 50.0-g Super Ball traveling at 29.0 m/s bounces off a brick wall and rebounds at 18.5 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.95 ms, what is the magnitude of the average acceleration of the ball during this time interval? In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at 67.0 m/s. The driver of the Thunderbird realizes that she must make a pit stop, and she smoothly slows to a stop over a distance of 250 m. She spends 5.00 s in the pit and then accelerates out, reaching her previous speed of 67.0 m/s after a distance of 300 m. At this point how far has the Thunderbird fallen behind the Mercedes Benz, which has continued at a constant speed?

Explanation / Answer

solution for 2 :

Ttortoise = L / vtortoise

Ttortoise = L /0.11

L = 0.11 X Ttortoise

tortoise wins by 35 cm = 0.35 m

then L - 0.35 = 20 X vtortoise ( Ttortoise - 180 )

0.11 X Ttortoise - 0.35 = 20 X vtortoise ( Ttortoise - 180 )

0.11 X Ttortoise - 0.35 = 20 X 0.11 X ( Ttortoise - 180 )

0.11 X Ttortoise - 0.35 = 2.2 X Ttortoise - 2.2 X 180

0.11 X Ttortoise - 2.2 X Ttortoise = - 396 + 0.35

-2.09 X Ttortoise = -396.35

Ttortoise = 396.35 / 2.09

Ttortoise = 189.64 sec

L = 0.11 X Ttortoise

L = 0.11 X 189.64

L = 20.86 m

solution for 3 :

v2 = 18.5 m / s

v1 = - 29 m/s

t = 3.95 m s = 3.95 X 10-3 s

average accelaration a = v2 - v1 / t

a = ( 18.5 - ( -29 ) ) / 3.95 X 10-3

a = 47.5 / 3.95 X 10-3

a = 12025.31 m /s2

solution 4 :

the total distance is covered by S

S = d1 + d2 + d3

S = 250 + 0 + 300

S = 550 m

the total time T

T = t1 + t2 + t3

T = 250 / 33.5 + 5 + 300 / 33.5

T = 7.46 + 5 + 8.95

T = 21.41 sec

Mercedes Benz is travelled by = v t

= 67 X 21.41

= 1434.47 m

the distance between them is

= 1434.47 - 550

distance = 884.47 m

The distance between them is now

1,537 - 550 = 937 m

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.