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
Sonbull [250]
2 years ago
11

If you can swim in still water at 0.5m/s, the shortest time it would take you to swim from bank to bank across a 20m wide river,

if the water flows downstream at a rate of 1.5m/s, is most nearly:

Physics
2 answers:
Mama L [17]2 years ago
6 0

Answer:42.55 seconds

Explanation:

Check attached file for the diagram.

Vr= velocity of the river, if the water flows downstream, which is equal to 1.5m/s(from the question), Vb= my velocity at angle alpha which is perpendicular to the x-axis, and c= distance to swim from river bank to the other river bank.

Therefore, the shortest time to be taken to swim or cross the river,t=river with width of C÷ vertical component Vj.

Note that (vector) Vj= (vector)Vr+(vector)Vb.

Also, alpha must be maximum and for that to happen it must have a value of one(1).

Hence, time taken to cross the river,t= C/Vb× sin (alpha).

t= 20m÷ 0.5 ×sin 90.

t= 20÷ 0.47.

t= 42.55 seconds.

expeople1 [14]2 years ago
4 0

Answer:

t=40s,

Explanation:

If you can swim in still water at 0.5m/s, the shortest time it would take you to swim from bank to bank across a 20m wide river, if the water flows downstream at a rate of 1.5m/s, is most nearly:

from the question the swimmer will have a velocity which is equal to the sum of the speed of the water and the velocity to swi across the bank

Vt=v1+v2

the time is takes to swim across the bank will be

DY=Dv*t

DY=distance across the bank

Dv=ther velocity of the swimmer across the bank

t=20/ 0.5m/s,

t=40s, time it takes to swim across the bank

velocity is the rate of displacement

displacement is distance covered in a specific direction

You might be interested in
The magnitude of a component of a vector must be
den301095 [7]
Less than or equal to the magnitude of the vector
6 0
2 years ago
A paleontologist measures the ratio of carbon-14 to carbon-12 in a fossil skull found at a site. What technique is he using and
pav-90 [236]
The corect anwser would be d
8 0
3 years ago
The orientation of which of the following does not influence the phases of the moon? a. Earth c. Sun b. the moon d. Stars Please
beks73 [17]
I'm pretty sure it's D. The stars don't influence the moon's phases.
6 0
3 years ago
What do you measure when you measure an object’s mass?
Effectus [21]

Answer:

how much space it takes up in the world

Explanation:

1) Mass is a measurement of the amount of matter something contains, while Weight is the measurement of the pull of gravity on an object. 2) Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. Weight is measured on a scale.

3 0
2 years ago
Heat can be transferred through conduction, convection, and radiation. What is necessary in order for heat to be transferred by
jeka94

it would be..... C

sorry if I am wrong I tryed to think, At least I try!

3 0
3 years ago
Read 2 more answers
Other questions:
  • Which condition would cause salinity of ocean water to decrease
    10·2 answers
  • What makes an object stop,<br> speed up, slow down or change<br> direction?<br> V2
    9·1 answer
  • which of the following can best help you in a risky situation? stay close to the quieter kids have an excuse ready so you can le
    14·2 answers
  • The three osicles known as the hammer, anvil and stirrup __________.
    11·1 answer
  • Two clowns are launched from the same spring-loaded circus cannon with the spring compressed the same distance each time. Clown
    6·1 answer
  • A helium balloon ride lifts up passengers in a basket. Assume the density of air is 1.28 kg/m3 and the density of helium in the
    9·1 answer
  • He had 5 dogs plus 2. Cats <br> How many did he have all together?
    9·2 answers
  • suppose that the earth were moved to a distance of 0.25 AU from the sun. How much stronger or weaker would the suns gravitationa
    15·1 answer
  • A horizontal force of 150 N is used to push a 38.0 kg packing crate a distance of 6.85 m on a rough horizontal surface. If the c
    5·1 answer
  • 3.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!