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
romanna [79]
3 years ago
11

A speedboat is approaching a dock at 25 m/s (56 mph). When the dock is 150 m away, the driver begins to slow down. a) What accel

eration must the boat have to come to a stop just as it arrives at the dock? b) If the braking acceleration of the boat has a maximum magnitude of 1.0 m/s^2-, how fast is the boat going when it hits the dock? Convert your result to mph. c) If the braking acceleration of the boat has a maximum magnitude of 1.0 m/s^2, at what distance from the dock should the driver have begun slowing down?
Physics
1 answer:
trasher [3.6K]3 years ago
5 0

Answer:

a) -2.038 m/s²

b) 40.33 mph

c) 312.5 m

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

v^2-u^2=2as\\\Rightarrow a=\frac{v^2-u^2}{2s}\\\Rightarrow a=\frac{0^2-25^2}{2\times 150}\\\Rightarrow a=-2.083\ m/s^2

Acceleration of the boat is -2.083 m/s² if the boat will stop at 150 m.

v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times -1\times 150+25^2}\\\Rightarrow v=18.03\ m/s

Speed of the boat by when it will hit the dock is 18.03 m/s

Converting to mph

1\ mile=1609.34\ m

1\ h=3600\ seconds

18.03\times \frac{3600}{1609.34}=40.33\ mph

Speed of the boat by when it will hit the dock is 40.33 mph

v^2-u^2=2as\\\Rightarrow s=\frac{v^2-u^2}{2a}\\\Rightarrow s=\frac{0^2-25^2}{2\times -1}\\\Rightarrow s=312.5\ m

The distance at which the boat will have to start decelerating is 312.5 m

You might be interested in
An electric generator transforms mechanical energy into electrical energy. This process could be done by which of these?
Dimas [21]

Answer:

its d

Explanation:

6 0
3 years ago
Read 2 more answers
What is meant by 'wasted energy'?
schepotkina [342]
Wasted energy is an energy which is transformed without significant use.
5 0
3 years ago
Read 2 more answers
A support crossbeam on a high speed train is made from a titanium rod that has a length of 0.650m when measured by an observer o
Vilka [71]

Answer:

A) The crossbeam is moving relative to the observer on the platform so the height appears contracted.

Explanation:

The observer on the train and the beam are in the same reference frame. That means observer on the train will measure the proper length of the beam not the contracted length . the observer is outside and the plank is in the moving system,it will appear to be moving.

3 0
3 years ago
A tennis ball with a velocity of +10.0 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball r
netineya [11]

Answer:

-1500 m/s2

Explanation:

So the ball velocity changes from 10m/s into the wall to -8m/s in a totally opposite direction within a time span of 0.012s. Then we can calculate the average acceleration of the ball as the change in velocity over a unit of time.

a = \frac{\Delta v}{\Delta t} = \frac{-8 - 10}{0.012} = \frac{-18}{0.012} = -1500 m/s^2

6 0
3 years ago
Why must objects be cooled before their mass is determined on a sensitive balance?
zubka84 [21]
Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
5 0
3 years ago
Other questions:
  • A toy car is given a quick push so that it rolls up an inclined ramp. After it is released, it rolls up, reaches its highest poi
    9·1 answer
  • A dinosaur and a mammoth elephant are walking away from each other in Jurassic Park When the mammoth is at a distance that is tw
    13·1 answer
  • A parallel-plate capacitor with circular plates of radius 0.19 m is being discharged. A circular loop of radius 0.28 m is concen
    10·1 answer
  • Find h , the maximum height attained by the projectile. express the maximum height in terms of v 0 , θ , and g .
    11·1 answer
  • (a) What is the angular speed ω about the polar axis of a point on Earth's surface at a latitude of 55° N? (Earth rotates about
    12·1 answer
  • Last night Mookie Betts hit a baseball at 32.5 m/s at a 45° angle. Betts
    15·1 answer
  • (show your work)
    10·1 answer
  • The following number - 0.050437 - written to TWO significant figures would be
    12·1 answer
  • What is velocity ratio? It is impossible to get a perfect machine in practical life, why?<br>​
    11·1 answer
  • Which unit of measure is the correct SIunit to use in measuring the mass of a boulder?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!