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
olga nikolaevna [1]
3 years ago
5

You're riding a unicorn at 25 m/s and come to a uniform stop at a red light 20m away. What's your acceleration?

Physics
2 answers:
NNADVOKAT [17]3 years ago
8 0

The answer is -15.625m/s².


Acceleration is the change in velocity over a period of time. It can be computed using the formula:


a = \dfrac{vf-vi}{t}

Where:

vf = final velocity

vi = initial velocity

t = time

Now let's see what was given in your problem:

The car was moving at 25m/s and then came to a stop. So initially it was moving and then it stopped. This means the final velocity will be 0m/s because it stopped moving.


But look at the problem, it shows no time. We need to solve for time from the time it moved till it reached the red light 20 m away.


Time can be computed using the kinematics formula:

d = \dfrac{vi+vf}{2} *t


We just derive the formula from the equation by filling out what we know first. 

20m = \dfrac{25m/s+0m/s}{2}(t)

20m = 12.5m/s{2}(t)

\dfrac{20m}{12.5m/s}=t
1.6s=t

The time it took from the point it was moving till it stopped is 1.6s. We can now use this in our acceleration formula.


a = \dfrac{0m/s-25m/s}{1.6s}

a = \dfrac{-25m/s}{1.6s}

a = -15.625m/s^{2}


Notice that the acceleration is negative. This means that the car decelerated or slowed down.

strojnjashka [21]3 years ago
5 0

Answer:

My acceleration is 15.63 m/s² (slowing down)

Explanation:

The expression for the acceleration is equal:

v^{2} _{f} -v^{2} _{i} =2ax

Where

vi = initial speed = 25 m/s

vf = final speed = 0

x = displacement = 20 m

Replacing and clearing the acceleration "a":

a=\frac{v^{2} _{f} -v^{2} _{i} }{2x} =\frac{0-25^{2} }{2*20} =--15.63m/s^{2}

The negative sign of acceleration means that it is slowing down

You might be interested in
A toy car goes over a small ramp at a horizontal velocity of 1.21 m/s and decelerates at 0.131 m/s2 while in the air. The total
xz_007 [3.2K]
We need to considerate only the horizontal component of the motion of the toy car.

The formula for the distance in a decelerated motion is:
s = s₀ + v₀·t - 1/2·a·t²

where:
s₀ = initial position = 0
v₀ = initial velocity = 1.21 m/s
t = time elapsed = 0.342 s
a = deceleration = 0.131 m/s²

Plugging in numbers:
s = 0 + 1.21×0.342 - 0.5×0.141×(0.342)²
  = 0.406 m

Hence, the toy car traveled a distance of about 41 cm.

3 0
3 years ago
Could I get help on this question please . My parents won’t help me /:
vovikov84 [41]

Answer:

Tarzan will be moving at 7.4 m/s.

Explanation:

From the question given above, the following data were obtained:

Height (h) of cliff = 2.8 m

Initial velocity (u) = 0 m/s

Final velocity (v) =?

NOTE: Acceleration due to gravity (g) = 9.8 m/s²

Finally, we shall determine how fast (i.e final velocity) Tarzan will be moving at the bottom. This can be obtained as follow:

v² = u² + 2gh

v² = 0² + (2 × 9.8 × 2.8)

v² = 0 + 54.88

v² = 54.88

Take the square root of both side

v = √54.88

v = 7.4 m/s

Therefore, Tarzan will be moving at 7.4 m/s at the bottom.

3 0
3 years ago
How much force is applied if a 130kg mass is accelerated at 5 m/s^2?​
STALIN [3.7K]

Answer:

650N

Explanation:

f= ma

130kg x 5 m/s^2 = 650N

5 0
3 years ago
An archer defending a castle is on an 15.5 m high wall. He shoots an arrow straight down at 22.8 m/s. How much time does it take
kodGreya [7K]

Answer:

  about 602 milliseconds

Explanation:

The motion can be approximated by the equation ...

  y = -4.9t^2 -22.8t +15.5

where t is the time since the arrow was released, and y is the distance above the ground.

When y=0, the arrow has hit the ground.

Using the quadratic formula, we find ...

  t = (-(-22.8) ± √((-22.8)^2 -4(-4.9)(15.5)))/(2(-4.9))

  = (22.8 ± √823.64)/(-9.8)

The positive solution is ...

  t ≈ 0.60195193

It takes about 602 milliseconds for the arrow to reach the ground.

8 0
3 years ago
Who sponsored Felix Baumgartner in the second space jump that took placed in<br> 2008?
KengaRu [80]

Alban Geissler, who developed the SKYRAY carbon fiber wing with Christoph Aarns, suggested after Baumgartner's jump that the wing he used was a copy of two prototype SKYRAY wings sold to Red Bull (Baumgartner's sponsor) two years earlier. - wiki

8 0
3 years ago
Other questions:
  • Which of these temperatures is likely when a container of water at 20° C is mixed with water at 28° C?
    13·1 answer
  • Which often results from great variations in a habitat’s abiotic conditions?
    9·2 answers
  • Which statement is true?
    15·1 answer
  • Which example best demonstrates how unbalanced forces change the speed of an object's motion? A) A child on a bicycle braking at
    15·2 answers
  • What are the 2 major organizations that develop symbols for use throughout different engineering disciplines
    8·1 answer
  • What are the steps of the scientific method?
    14·2 answers
  • Một ô tô đi với vận tốc 60 km/h trên nửa phần đầu của đoạn đường AB. Trong nửa đoạnđường còn lại ô tô đi nửa thời gian đầu với v
    15·1 answer
  • A cheetah running initially at a velocity of 20 m/s accelerates
    15·1 answer
  • What can be correctly concluded from this experiment?
    8·2 answers
  • If the energy in a mechanical wave increases or decreases, what is also going to increase or decrease? A wavelength B amplitude
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!