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
skelet666 [1.2K]
3 years ago
15

John has a boat that will travel at the rate of 15 kph in still water. he can go upstream for 35 km in the same time it takes to

go 140 km downstream. how fast is his boat traveling when he goes downstream? 22 kph 24 kph 26 kph
Physics
1 answer:
MA_775_DIABLO [31]3 years ago
5 0
Let F = the downstream speed of the water. 

<span>Then the boat's upstream speed is: 15 - F </span>
<span>The boat's downstream speed is: 15 + F </span>


<span>Assume both the journeys mentioned take T hours, then using "speed x time = distance" we get: </span>

<span>Downstream journey: (15 + F)T = 140 </span>
<span>Upstream journey: (15 - F)T = 35 </span>


<span>Add the two formulae together: </span>

<span>(15 + F)T + (15 - F)T = 140 + 35 </span>

<span>15T + FT + 15T - FT = 175 </span>

<span>30T = 175 </span>

<span>T = 35/6 </span>


<span>Use one of the equations to find F: </span>

<span>(15 + F)T = 140 </span>

<span>15 + F = 140/T </span>
<span>F = 140/T - 15 </span>
<span>F = 140/(35/6) - 15 </span>
<span>F = 24 - 15 </span>
<span>F = 9 </span>

<span>i.e. the downstream speed of the water is 9 kph </span>

<span>Therefore, the boat's speed downstream is 15 + F = 15 + 9 = 24 kph.
the answer is:                       *24kph*</span>
You might be interested in
Calculate the amount of heat needed to melt 35.0 g of ice at 0 ºC.Express your answer in kilojoules
PolarNik [594]
The amount of heat will be equal to Lm.

Where L is the latent heat of fusion and m is mass of the ice.

Latent heat of ice = 80cal/g.

So the amount of heat required here will be 35× 80cal

= 2,800 cal.
6 0
3 years ago
Read 2 more answers
The diagram below outlines the appeals path through a state court system.
dexar [7]

Answer:

B sorry if im wrong

Explanation:

4 0
3 years ago
Read 2 more answers
Which test was conducted on the skin found under the victim’s nails?
BARSIC [14]
Y-STR analysis. It is a DNA test used to compute and match with the possibility via lap.
5 0
3 years ago
Read 2 more answers
Hello everyone. This is a question about Dimensional Analysis and I came across this question but I am unable to wrap my head ar
omeli [17]

Answer:

2. [B] = [L]/[T] and [C] = [L]/[T]

Explanation:

I assume you mean this:

A = B² + 2B⁴/C²

Since you can't add numbers with different units (for example, you can't add seconds to meters), each term in the sum must have the same units as A.

B² = [L]²/[T]²

B = [L]/[T]

B⁴/C² = [L]²/[T]²

C²/B⁴ = [T]²/[L]²

C² = B⁴ [T]²/[L]²

C² = ([L]/[T])⁴ [T]²/[L]²

C² = [L]²/[T]²

C = [L]/[T]

Notice we ignore the 2 coefficient, which is unitless.

7 0
3 years ago
After coming down a slope, a 60-kg skier is coasting northward on a level, snowy surface at a constant 15 m&gt;s. Her 5.0-kg cat
Vinil7 [7]

To solve this exercise, it is necessary to apply the concepts of conservation of the moment especially in objects that experience an inelastic colposition.

They are expressed as,

m_1v_1+m_2v_2 = (m_1+m_2)v_f

Where,

m_1= mass of the skier

m_2= mass of the cat

v_1 = initial velocity of skier

v_2 = initial velocity of cat

v_f= final velocity of both

Re-arrange to find V_f we have,

V_f = \frac{m_1v_1+m_2v_2}{(m_1+m_2)}

V_f = \frac{(60)(15)+(5)(-3.8)}{(60+5)}

V_f = 13.55m/s

Once the final velocity is found it is possible to calculate the change in kinetic energy, so

\Delta KE = KE_i-KE_f

\Delta KE = \frac{1}{2}(m_1v_1^2+m_2v^2_2)-\frac{1}{2}(m_1+m_2)v_f^2

\Delta KE = \frac{1}{2}((60)(15)^2+(5)(-3.8)^2)-\frac{1}{2}(60+5)(13.55)^2

\Delta KE = 819.1J

Therefore the amount of kinetic energy converted in to internal energy is 819J

3 0
3 years ago
Other questions:
  • What is responsible for the production of x ray emission at the cutoff wavelength?
    15·1 answer
  • A balloon starts rising from rest from the ground with an acceleration of 1.25 m/s2. After 8s, a stone is released from the ball
    10·1 answer
  • When adding vectors in the x and y direction, what must you do to find the magnitude and direction of the resultant vector?
    8·1 answer
  • Are bases chemically the same as acids true or false
    15·1 answer
  • A rocket travels 600m while being accelerated uniformly from rest at a rate
    5·1 answer
  • A lens is designed to work in the visible, near-infrared, and near-ultraviolet. The best resolution of this lens from a diffract
    6·1 answer
  • A group of particles of total mass 35 kg has a total kinetic energy of 313 J. The kinetic energy relative to the center of mass
    7·1 answer
  • What type of electromagnetic wave is a TV remote and a cloud
    15·1 answer
  • What is a quasar made of?
    12·1 answer
  • 11 An unstretched spring is 12,0 cm long. A load of 5.0N stretches it to 15.0cm. How long will it be under a load
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!