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
dezoksy [38]
3 years ago
5

David rowed a boat upstream for three miles and then returned to point he started from. The entire journey took four hours. The

speed of the stream is one mile per hour. Find David's speed in still water. (Hint: speed = distance ÷ time, upstream speed = speed of the boat – speed of the stream, and downstream speed = speed of the boat + speed of the stream)
David's speed in still water is ____ miles per hour.
Physics
1 answer:
frez [133]3 years ago
4 0
Upstream speed = S - 1
Downstream speed = S + 1

Average speed = total distance / total time

Average speed = (S - 1) + (S + 1) / 2
= S

S = 6 miles / 4 hours
S = 1.5 miles per hour
You might be interested in
A country is deciding what to do about pollution glven off by power plants.
DENIUS [597]

Answer:

option B is the correct answer

Explanation:

please follow me and Mark me brainliest please

3 0
2 years ago
All rules to find work in changing force in physics ​
saw5 [17]

Answer:

FORCE - rate of change of momentum, ie its changing velocity [change in velocity is of more concern] NEWTON

WORK - product of force and displacement, ie [velocity may be constant or variable but change in position with certain force is of more concern] JOULES

I hope you understood from this..

7 0
2 years ago
A 5 kg bowling ball with a velocity of +10 m/s collides with a stationary 2 kg bowling pin. If the ball's final velocity is +8 m
Whitepunk [10]

Answer:

<h2>The pin's final velocity is 5m/s</h2>

Explanation:

Step one:

given data

mass of ball m1=5kg

initial velocity of ball u1=10m/s

mass of pin m2=2kg

initial velocity of pin u2= 0m/s

final velocity of ball v2=8m/s

final velocity of pin v2=?

Step two:

The expression for elastic collision is given as

m1u1+m2u2=m1v1+m2v2

substituting we have

5*10+2*0=5*8+2*v2

50+0=40+2v2

50-40=2v2

10=2v2

divide both sides by 2

v2=10/2

v2=5m/s

The pin's final velocity is 5m/s

3 0
3 years ago
What confirms that the process of seafloor spreading is occurring?
olga55 [171]
Mid ocean ridges
The mountain ranges in the middle of the oceans
Sea floor spreading
The process by which new, oceanic crust forms along a mid ocean ridge and older crust moves away from the ridge. :)
3 0
2 years ago
The car's initial speed was 15 m / s and the distance the car travels before it comes to a complete stop after the driver applie
pentagon [3]

Initial speed of the car (u) = 15 m/s

Final speed of the car (v) = 0 m/s (Car comes to a complete stop after driver applies the brake)

Distance travelled by the car before it comes to halt (s) = 63 m

By using equation of motion, we get:

\bf \longrightarrow  {v}^{2}  =  {u}^{2}  + 2as \\  \\ \rm \longrightarrow  {0}^{2}  =  {15}^{2}  + 2 \times a \times 63 \\  \\ \rm \longrightarrow 0 = 225 + 126a \\  \\ \rm \longrightarrow 126a =  - 225 \\  \\ \rm \longrightarrow a =  -  \dfrac{225}{126}  \\  \\ \rm \longrightarrow a =  - 1.78 \: m {s}^{ - 2}

\therefore Acceleration of the car (a) = -1.78 m/s²

Magnitude of the car's acceleration (|a|) = 1.78 m/s²

5 0
3 years ago
Other questions:
  • What units are used in the periodic table for atomic mass?
    14·2 answers
  • Earth's _____ cycle moves water from one reservoir to another. This cycling of materials is one of Earth's dynamic processes.
    5·2 answers
  • I do not know where to start.
    5·1 answer
  • Explain which planets have seasons and why some planets have none at all.
    11·1 answer
  • Ok these are my last points say hi if u want brainliest
    14·2 answers
  • I NEED HELP THIS QUESTION IS SO HARDDD!!
    11·2 answers
  • A computer simulation is an example of what?
    6·1 answer
  • A torque of 36.5 N · m is applied to an initially motionless wheel which rotates around a fixed axis. This torque is the result
    9·1 answer
  • Which organ allows the exchange of oxygen and carbon dioxide?​
    15·2 answers
  • Which of these statements best describes the relationship between elements, compounds, and pure substances? (2 points)
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!