1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vampirchik [111]
3 years ago
12

In April 1974, Steve Prefontaine completed a 10.0 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.43 km mark a

t a time of 25.0 min . If he accelerated for 60 s and then maintained his increased speed for the remainder of the race, calculate his acceleration over the 60 s interval. Assume his instantaneous speed at the 7.43 km mark was the same as his overall average speed up to that time.
Physics
1 answer:
Novay_Z [31]3 years ago
8 0

Answer:

Acceleration, a = 0.101 m/s²

Explanation:

Average speed = total distance / total time.

At the 7.43km mark, total distance = 7.43km or 7430m

Total time = 25 * 60 s = 1500s

Average speed = 7430m/1500s = 4.95m/s

He then covers (10 - 7.43)km = 2.57 km = 2570 m

in t = 27m43.6s - 25min = 2m43.6s = 163.6 s

Then he accelerates for 60 s, and maintains this velocity V, for the remaining (163.6 - 60)s = 103.6 s.

From V = u + at; V = 4.95m/s + a *60s

Distance covered while accelerating is

s = ut + ½at² = 4.95m/s * 60s + ½ a *(60s)² = 297m + a*1800s²

Distance covered while at constant velocity, v after accelerating is

D = velocity * time

Where v = 4.95m/s + a*60s

D = (4.95m/s + a*60s) * 103.6s = 512.82m + a*6216s²

Total distance covered after initial 7.43 km, S + D = 2570 m, so

2570 m = 297m + a*1800s² + 512.82m + a*6216s²

2570 = 809.82 + a*8016

a = 809.82m / 8016s² = 0.101 m/s²

You might be interested in
.<br><img src="https://tex.z-dn.net/?f=25%20%7B%3F%7D%5E%7B%3F%7D%20%20%5Ctimes%20%5Cfrac%7B%3F%7D%7B%3F%7D%20" id="TexFormula1"
mr_godi [17]

Answer:

what is your exact question.

5 0
2 years ago
Read 2 more answers
the distance between any two bodies is 10 M and the gravitational force between them is 3.2×10-⁹m. if the mass of one object is
cluponka [151]

Answer:

0.8 x 10^-9 kg

Explanation:

Given,

Distance ( R ) = 10 m

Force ( F ) = 3.2 x 10^-9 N

Mass ( m1 ) = 40 kg

To find : Mass ( m2 ) = ?

Formula : -

F = m1.m2 / R^2

m2 = FR^2 / m1

= 3.2 x 10^-9 x 10 / 40

= 3.2 x 10^-9 / 4

= ( 3.2 / 4 ) x 10^-9

m2 = 0.8 x 10^-9 kg

3 0
3 years ago
How are base units and derived units related?
Vlad1618 [11]

Answer:

SI derived units

Other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units.

Explanation:

Hope this helps :D

8 0
3 years ago
How would life on earth be different if its axis was not tilted with respect to its orbit?.
borishaifa [10]

Answer:

oone side at a time would be hot and the other oone

Explanation:

One side will be hot and the other cold no in-between

3 0
2 years ago
From the list below, which name appears in two different parts of the body? *
Kisachek [45]

Answer:

Ngjfibfubbb

Explanation:

7 0
2 years ago
Other questions:
  • Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. use each word only o
    11·1 answer
  • You throw a ball upwards at 22 m/s. How high will it go?
    13·2 answers
  • How can electricity be compared to water?
    13·1 answer
  • Deduce an expression for the gravitational potential
    7·1 answer
  • Only 2 questions plz answer.
    6·2 answers
  • A car which is traveling at a velocity of 1.6 m/s undergoes an acceleration of 9.2 m/s over a distance of 540 m. How fast is it
    5·1 answer
  • How do collisions affect the momentum of objects?<br> HELP ASAP
    13·1 answer
  • Which box will not accelerate?
    15·2 answers
  • What is science notation
    7·2 answers
  • How much potential energy does an 8 kg flower pot hanging 5 m above the ground have
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!