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
ryzh [129]
3 years ago
12

A speedboat moving at 28 m/s approaches a no-wake buoy marker 91 m ahead. The pilot slows the boat with a constant acceleration

of 4 m/s2 by reducing the throttle. What is the velocity (in m/s) of the boat when it reaches the buoy
Physics
1 answer:
Tpy6a [65]3 years ago
6 0

Answer:

7.5 m/s

Explanation:

We can find its velocity when it reaches the buoy by applying one of Newton's equations of motion:

v^2 = u^2 + 2as

where v = final velocity

u = initial velocity

a = acceleration

s = distance traveled

From the question:

u = 28 m/s

a = -4 m/s^2

s = 91 m

Therefore:

v^2 = 28^2 + 2 * (-4) * 91\\\\v^2 = 784 + -728 = 56\\\\v = \sqrt{56}\\ \\v = 7.5 m/s

The velocity of the boat when it reaches the buoy is 7.5 m/s.

You might be interested in
Which energy transformation occurs in the core of a nuclear reactor?
romanna [79]
The correct answer among the choices given is option B. The energy transformation that occurs in the core of a nuclear reactor is from nuclear energy to thermal energy. In a power plant nuclear fission which involves nuclear energy to heat up water around it. This part is  the core of the process.
5 0
3 years ago
Name of a body that changes Chemical energy to electric energy.​
Ratling [72]

Answer:

battery

Explanation:

A battery contains stored chemical energy and converts it to electrical energy. (cK.12)

6 0
3 years ago
Theweight ofof body is 420N .Calculate its mass​
Nady [450]

Answer:

42.87

Explanation:

Google

<u>OR</u>

<u></u>

420/9.8 which equals 42.87.

6 0
3 years ago
A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory
____ [38]

At the highest point in its trajectory, the ball's acceleration is zero but its velocity is not zero.

<h3>What's the velocity of the ball at the highest point of the trajectory?</h3>
  • At the highest point, the ball doesn't go more high. So its vertical velocity is zero.
  • However, the ball moves horizontal, so its horizontal component of velocity is non - zero i.e. u×cosθ.
  • u= initial velocity, θ= angle of projection

<h3>What's the acceleration of the ball at the highest point of projectile?</h3>
  • During the whole projectile motion, the earth exerts the gravitational force with a acceleration of gravity along vertical direction.
  • But as there's no acceleration along vertical direction, so the acceleration along vertical direction is zero.

Thus, we can conclude that the acceleration is zero and velocity is non-zero at the highest point projectile motion.

Disclaimer: The question was given incomplete on the portal. Here is the complete question.

Question: Player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

A- neither the ball's velocity nor its acceleration are zero.

B- the ball's acceleration points upward.

C- the ball's acceleration is zero but its velocity is not zero.

D- the ball's velocity points downward.

Learn more about the projectile motion here:

brainly.com/question/24216590

#SPJ1

7 0
2 years ago
An inventor claims to have developed a power cycle having a thermal efficiency of 40%, while operating between hot and cold rese
lesya [120]

From Carnot's theorem, for any engine working between these two temperatures:


efficiency <= (1-tc/th) * 100


Given: tc = 300k (from question assuming it is not 5300 as it seems)

For a, th = 900k, efficiency = (1-300/900) = 70%

For b, th = 500k, efficiency = (1-300/500) = 40% 

For c, th = 375k, efficiency = (1-300/375) = 20% 


Hence in case of a and b, efficiency claimed is lesser than efficiency calculated, which is valid case and in case of c, however efficiency claimed is greater which is invalid. 

7 0
3 years ago
Other questions:
  • An electron with kinetic energy 2.9 keV moving along the positive direction of an x axis enters a region in which a uniform elec
    14·1 answer
  • Given that an atom of a semiconductor has a diameter of 2.18 å , what is the maximum number of moles that fit in the channel of
    9·1 answer
  • What is the rate at which energy is transformed from one form to another called?
    12·1 answer
  • Velocity of a car that travled 120 miles in 2 hours
    13·2 answers
  • A portable television using a 12 volt, 3 Ah rechargeable battery can operate for a period of about 6 hours. What is the average
    7·1 answer
  • Find the angle between the vectors |A+B|=|A-B|​
    9·1 answer
  • A heavy sled and a light sled, both moving horizontally with the same speed, suddenly slide onto a rough patch of snow and event
    14·2 answers
  • Two coins lie 1.5 meters apart on a table. They carry identical electric charges. Approximately how
    5·1 answer
  • Asexual reproduction involves only one parent. The offspring of this type of reproduction have - F DNA identical to the DNA of t
    13·1 answer
  • A car travels at 20km/h for 60 mins how far does it travel
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!