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]
2 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]2 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
PLease Help!
scoundrel [369]

Answer:

Option A is the correct answer.

Explanation:

The instantaneous acceleration = Change in velocity in velocity/Time taken

The slope of the graph should give instantaneous acceleration.

 Slope of a graph = Change in value of Y -axis / Change in values of X -axis

 Comparing both the equations

   Change in value of Y -axis = Change in velocity in velocity

   Change in values of X -axis = Time taken

So velocity values should be on the Y axis and Time values should be on the X axis.

Option A is the correct answer.

8 0
3 years ago
True / False
devlian [24]
1. True
2. True
3. True
4. True
5. False
6. False
7. True
8 0
2 years ago
Read 2 more answers
A spherical helium filled balloon (B) with a hanging passenger cage being held by a single vertical cable (C) attached to Earth
Gre4nikov [31]

Answer:

The tension is  T  = 4326.7 \  N

Explanation:

From the question we are told that

   The  total mass is  m  =  200 \  kg

    The  radius is r = 5 \  m

     The  density of air is  \rho_a  =  1.225 \ kg/m^3

Generally the upward  force acting on the balloon is mathematically represented as

        F_N  =   T  + mg

=>     (\rho_a  *  V  *  g ) =   T  + mg

=>   T  =  (\rho_a  * V  *  g   )  - mg

Here V is the volume  of the spherical helium filled balloon which is mathematically represented as

      V  =  \frac{4}{3}  * \pi r^3

=>   V  =  \frac{4}{3}  * 3.142 *(5)^3

=>   V  = 523.67\  m^3

So

    T  = (1.225 *  523.67*  9.8 ) -  200 *  9.8

   T  = 4326.7 \  N

5 0
2 years ago
A dumbell has a mass of 95 kg. What force must be applied to accelerate it upward at 2.2 m/s2?
Sveta_85 [38]
A :-) F = ma
Given - m = 95 kg
a = 2.2 m/s^2
Solution -
F = ma
F = 95 x 2.2
F = 209

.:. The force is 209 N
5 0
2 years ago
Why do clouds form? hurryyyyyyy
gavmur [86]
If there is a large enough amount of water vapor in the air and the tempature is hot enough cloud or storms can form.
5 0
2 years ago
Read 2 more answers
Other questions:
  • following statement supports which theory? "Astronomers have observed protoplanetary disks around distant newborn stars." Big Ba
    8·2 answers
  • Bena thinks that dissolving more salt in water causes the mixture’s freezing temperature to change.
    10·2 answers
  • You spy on an anchor on the bottom of a lake. What is the direction and amount of force the water exerts on it: a) zero
    14·1 answer
  • The density of aluminum is 2.7 g/cm3. What is the volume of a piece of aluminum if its mass is 8.1 grams?
    12·1 answer
  • Which one of the following is an example of an indicator?
    7·1 answer
  • Two similar gold spheres are separated by a distance of
    12·1 answer
  • Does the mass of a supermassive black hole correlate with any other part of a galaxy?
    13·1 answer
  • What are the maria composed of? Is this material found elsewhere in the solar system?
    8·1 answer
  • A rock falls from a vertical cliff that is 4.0 m tall and experiences no significant air resistance as it falls. At what speed w
    15·1 answer
  • Please help
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!