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
Oksanka [162]
3 years ago
14

ear the end of a marathon race, the first two runners are separated by a distance of 45.0 m. The front runner has a velocity of

3.45 m/s, and the second a velocity of 4.25 m/s. (a) What is the velocity (in m/s) of the second runner relative to the first? m/s faster than the front runner (b) If the front runner is 250 m from the finish line, who will win the race, assuming they run at constant velocity? The first runner will win. The second runner will win. (c) What distance (in m) ahead will the winner be when she crosses the finish line? m
Physics
2 answers:
sesenic [268]3 years ago
6 0

Answer:

a) V_{2/1}=0.8m/s

b) The second runner will win

c) d = 10.54m

Explanation:

For part (a):

V_{2/1} = V_{2} - V_{1} = 0.8m/s

For part (b) we will calculate the amount of time that takes both runners to cross the finish line:

t_{1} = \frac{X_{1}}{V_{1}}=\frac{250}{3.45}=72.46s

t_{2} = \frac{X_{2}}{V_{2}}=\frac{250+45}{4.25}=69.41s

Since it takes less time to the second runner to cross the finish line, we can say the she won the race.

For part (c), we know how much time it takes the second runner to win, so we just need the position of the first runner in that moment:

X1 = V1*t2 = 239.46m  Since the finish line was 250m away:

d = 250m - 239.46m = 10.54m

SpyIntel [72]3 years ago
4 0

Answer:

At the time t = 0, the distance is 45m

the front runer has a velocity of 3.45 m/s, the second one has a velocity of 4.25 m/s

then the position of both runes, puting the zero of the position where the runer 1 is:

p1(t) = (3.45m/s)*t

p2(t)= (4.25m/s)*t - 45m

a) relative velocity: this is the differenceof both velocities: v2 - v1 = 4.25m/s - 3.45m/s = 0.8m/s

this means that the first runner sees the second one with a positive velocity.

b) if the first runner is 250m away from the finish line, then:

the first runner needs:

p1(t) = 250m = (3.45m/s)*t

t = (250/3.45) s = 72.5 seconds

for the runner 2

p2(t) = 250m = (4.25m/s)*t - 45m

250m + 45m = 295m = (4.25m/s)*t

(295/4.25) s = t = 69.4 seconds

So the runner 2 needs less time, this means that he will reach the finish line first

c) we know that at t= 69.4 seconds, the second runner is in the finish line, we can imput that thime in the position of the runner 1:

p1(69.4s) = (3.45m/s)*69.4s = 239.5m

and at this time, the runner 2 is already at the finish line that was 250m away from the first runner, so the distance is:

250m - 239.5m = 10.5m

You might be interested in
Which colors allowed the most electricity to be generated
Naddik [55]
Yellow and red hope that helped
3 0
3 years ago
How to derive the fourth equation of motion?
Leya [2.2K]

Answer:

To derive the fourth equation of motion, first we have to consider the equation for acceleration and then to rearrange it. or v2 = u2 + 2as and this equation of motion can be used to find the final velocity or the distance travelled if the other values are given.

Explanation:

v= u + at

s =( u + v ) t /2

s = ut + at2/2

v2 = u2 + 2as

6 0
3 years ago
Inside a NASA test vehicle, a 3.50-kg ball is pulled along by a horizontal ideal spring fixed to a friction-free table. The forc
erastova [34]
F(of spring)=230x=ma=3.5(5)=17.5=230x; x=0.07m.
3 0
2 years ago
A van is traveling on a road at a speed of 55 km/h. A girl sitting near the driver of the van throws a paper airplane to a boy a
aivan3 [116]
<span>A van is traveling on a road at a speed of 55 km/h relative to a
stationary observer on the side of the road. A girl sitting near the
driver of the van throws a paper airplane to a boy at the back of the
van with a speed of 2 km/h relative to the girl, the boy, and the van.

The speed of the paper airplane, relative to the same stationary observer
on the side of the road, is (55 - 2) = 53 km/h.  No rounding is necessary.</span>
5 0
3 years ago
Read 2 more answers
Which are functions of proteins?
NikAS [45]
D. to be structural material
5 0
3 years ago
Read 2 more answers
Other questions:
  • What is the displacement for a driver who travels 10 km to get to a point that is 4 km from his starting point?
    5·1 answer
  • An object at 20∘c absorbs 25.0 j of heat. what is the change in entropy δs of the object?
    13·2 answers
  • 20. Consider two Stars A and B with temperatures Ta and TB and radii Ra and RB respectively. If TA
    12·1 answer
  • How can you tell when an object changes direction on a displacement vs. time graph
    10·1 answer
  • A wagon is pulled for a distance of 5 meters in 20 seconds with a work output of 75 j. what is correct unit label for power outp
    5·1 answer
  • GIVING BRAINLIEST PLEASE HELP!!
    11·1 answer
  • ELE Review questions
    12·1 answer
  • A constant electric field of 5.00 N/C points along the positive x-direction. An electron, initially at rest, moves a distance of
    12·1 answer
  • 2. An auditorium has 58 seats in the first row, 62 seats in the second row, 66 seats in the third row, and so
    15·1 answer
  • according to karl popper, a discipline that claims to be a science is really a pseudoscience like astrology if it:
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!