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
kondor19780726 [428]
3 years ago
15

A boat moves through the water of a river at 4.72 m/s relative to the water, regardless of the boat’s direction. If the current

is flowing at 3.86 m/s, how long does it take the boat to complete a trip consisting of a 297 m displacement downstream followed by a 389 m displacement upstream? Answer in units of s.
Physics
2 answers:
Tems11 [23]3 years ago
7 0

Answer:

486.95s

Explanation:

Let the velocity of the boat be v_b and that of the river be v_r.

When the boat is moving downstream, the resultant velocity is given by;

v=v_b+v_r\\Given;\\v_b=4.72m/s\\v_r=3.86m/s\\therefore\\v=4.72m/s+3.86m/s=8.58m/s

Recall that

velocity=\frac{dispacement}{time}.............(1)

Given; downstream displacement, d = 297m. Therefore by equation (1);

8.58=\frac{297}{t_1}\\t_1=\frac{297}{8.58}\\t_1=34.62s

where t_1 is the time taken to travel downstream displacement.

When the boat is moving upstream it is moving directly against the river current, hence its resultant velocity in this case becomes;

v=v_b-v_r\\v=4.72-3.86=0.86m/s

The time taken upstream is then calculated as follows given that the upstream displacement is 389m, according to equation (1);

0.86=\frac{389}{t_2}\\

therefore t_2=\frac{389}{0.86}=452.326s

Hence the total time taken by the boat to complete its trip as specified is given as follows;

t_{total}=t_1+t_2= 34.62+452.326\\t_{total}=486.95s

Setler [38]3 years ago
5 0

Answer:

Total time taken by boat to cover all the displacement = 452.3254 sec

Explanation:

We have given speed of boat = 4.72 m/sec

Speed of current flowing = 3.86 m./sec

In downstream relative speed of boat = speed of boat + speed of current flowing = 4.72+3.86 = 8.58 m/sec

Distance traveled downstream = 297 m

So time taken by boat to travel 297 m downstream t_1=\frac{297}{8.58}=34.615sec

In upstream relative speed of speed = speed of boat - speed of current flowing = 4.72 -3.86 = 0.86 m/sec

Distance traveled in upstream = 389 m

So time taken to travel 289 m upstream t_2=\frac{389}{0.86}=452.325sec

So total time t=t_1+t_2=34.615+452.325486.94 sec

You might be interested in
Clara rushes 30m to a truck then turns and walks back. Total travel is 120s what is her average velocity?
navik [9.2K]

Taking into account the definition of velocity, Clara's average velocity is 0.5 m/s.

<h3>Definition of velocity</h3>

Velocity is a physical magnitude that relates the displacement of an object, the time it takes to make this change in position and direction. So it is considered a vector magnitude.

In other words, the velocity can be defined as the amount of space traveled per unit of time with which a body moves, considering the direction, and can be calculated using the expression:

velocity= distance traveled÷ time

<h3>Average velocity of Clara</h3>

Clara rushes 30 m to a truck then turns and walks back. Total travel is 120s. Then, you know:

  • distance traveled= 30m rushing + 30m walking back= 60 m
  • time= 120 s

Replacing in the definition of velocity:

velocity= 60 m÷ 120 s

Solving:

<u><em>velocity= 0.5 m/s</em></u>

Finally, Clara's average velocity is 0.5 m/s.

Learn more about velocity:

brainly.com/question/4418301

brainly.com/question/24990123

brainly.com/question/14244558

brainly.com/question/25288184

#SPJ1

5 0
2 years ago
3. Convert 588 km/hr to m/s.​
Luden [163]

Answer:

= 163.3 m/sec

hope it helps

7 0
3 years ago
Problem:
pav-90 [236]

Answer:

Total energy is constant

Explanation:

The laws of thermodynamics state that thermal energy (heat) is always transferred from a hot body (higher temperature) to a cold body (lower temperature).

This is because in a hot body, the molecules on average have more kinetic energy (they move faster), so by colliding with the molecules of the cold body, they transfer part of their energy to them. So, the temperature of the hot body decreases, while the temperature of the cold body increases.

This process ends when the two bodies reach the same temperature: we talk about thermal equilibrium.

In this problem therefore, this means that the thermal energy is transferred from the hot water to the cold water.

However, the law of conservation of energy states that the total energy of an isolated system is constant: therefore here, if we consider the hot water + cold water as an isolated system (no exchange of energy with the surroundings), this means that their total energy remains constant.

4 0
3 years ago
The Burj Khalifa in Dubai is the world's tallest building. The structure is 828 m 828 m (2716.5 ft) and has more than 160 storie
Natasha_Volkova [10]

Answer:

h = height of the hotel room from the ground floor = 237.4m

Explanation:

Change in Potential Energy of tourist = ΔPE = PE2 – PE1 = mgh

PE1 is the potential energy of tourist at the ground floor

PE1 is the potential energy of tourist at the top (hotel room)

Given

PE1 = − 2.01 × 10⁵ J

PE2 = 0J

PE2 – PE1 = mgh

0 – (− 2.01 × 10⁵ J) = mgh

2.01 × 10⁵ J = 86.4×9.8×h

h = 2.01 × 10⁵/(86.4×9.8) = 237.4m

8 0
3 years ago
Which of the following is Not true about the noble gases
Alexandra [31]
Noble gases are not highly reactive
3 0
3 years ago
Other questions:
  • Rutherford proposed that
    13·1 answer
  • Rahul sits in a chair reading a book. Which force is equal to the force Rahul exerts on Earth?
    10·2 answers
  • A bicyclist notes that the pedal sprocket has a radius of rp = 11 cm while the wheel sprocket has a radius of rw = 4.5 cm. The t
    11·1 answer
  • Physical Science AIS - AE 20-21-Kotal / Unit 2: Reactions and Radioactivity / The Environment
    14·1 answer
  • 1. How much heat energy is required to raise the temperature of a 5 kg aluminium bar
    14·1 answer
  • A rock falls from a tower that is 320 feet high. As it is​ falling, its height is given by the formula h equals 320 minus 16 t s
    15·1 answer
  • All of the following are examples of ways to improve energy efficiency of heating systems, except _______.
    12·1 answer
  • A simple harmonic oscillator completes 1550 cycles in 30 min. (a) Calculate the period. s (b) Calculate the frequency of the mot
    13·1 answer
  • What is the speed od sail boat that us traveling 100 meters in 120 seconds?​
    14·1 answer
  • Which would take longer to cool off by 50 degrees, 1 kg of Copper or 1 kg of liquid water?
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!