All categories

3 years ago

A car is traveling at 70 km/h. It then uniformly decelerates to a complete stop in 12 s. Find its acceleration ( in m/s2 ).

Physics

2 answers:

Lera25 [3.4K]3 years ago

8 0

Answer:

- 1.62 m/s²

Explanation:

initial velocity, u = 70 km/h = 19.44 m/s

time, t = 12 s

final velocity, v = 0

Acceleration is defined by the rate of change of velocity.

By use of first equation of motion

v = u + a t

where, a be the acceleration

0 = 19.44 + a x 12

a = - 1.62 m/s²

Thus, the acceleration is - 1.62 m/s².

Yakvenalex [24]3 years ago

5 0

Answer:

Acceleration will be $-1.620m/sec^2$

Explanation:

We have given initial speed of the car is 70 km/hr

We know that 1 km = 1000 m

And 1 hour = 3600 sec

So $70km/hr=70\times \frac{1000m}{3600sec}=19.444m/sec$

It is given that car stops in 12 sec

So final speed of the car v = 0 m/sec

Time t = 12 sec

From first equation of motion v = u+at

So $0=19.444+a\times 12$

$a=\frac{-19.444}{12}=-1.620m/sec^2$ ( negative sign indicates that speed of the car will constantly decrease )

You might be interested in

Which of the following is true concerning nuclear fusion?

Artyom0805 [142]

Choice-a is a very rubbery, imprecise, ambiguous, slippery statement. But it's probably less wrong than any of the other choices on the list.

6 0

3 years ago

A diverging lens (f1 = -12.0cm) is located 50.0 cm to the left of a converging lens (f2 = 34.0 cm). A 2.0 cm-tall object stands

pishuonlain [190]

Answer:

The final image relative to the converging lens is 34 cm.

Explanation:

Given that,

Focal length of diverging lens = -12.0 cm

Focal length of converging lens = 34.0 cm

Height of object = 2.0 cm

Distance of object = 12 cm

Because object at focal point

We need to calculate the image distance of diverging lens

Using formula of lens

$\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{u}$

$\dfrac{1}{v}=\dfrac{1}{-12}-\dfrac{1}{-12}$

$v=\infty$

The rays are parallel to the principle axis after passing from the diverging lens.

We need to calculate the image distance of converging lens

Now, object distance is ∞

Using formula of lens

$\dfrac{1}{v}=\dfrac{1}{34}-\dfrac{1}{\infty}$

$v=34$

The image distance is 34 cm right to the converging lens.

Hence, The final image relative to the converging lens is 34 cm.

5 0

3 years ago

A rollercoaster car has 2500 J of potential energy and 160 J of

lara31 [8.8K]

Answer:

E_{k2}=2660 [J] kinetic energy.

Explanation:

The energy in the initial state i.e. when the rollercoaster is at the top is equal to the energy in the final state i.e. when it is at the bottom of the hill.

These states can be represented by means of the second equation.

$E_{k1}+E_{p1}=E_{k2}\\160 + 2500 = E_{k2}\\E_{k2}=2660 [J]$

Since the rollercoaster is located in the bottom of the hill where the potential energy level is zero, therefore there is only kinetic energy in the second state.

8 0

3 years ago

Why does a Ray of light passing through a glass slab not shown dispersion?

Hatshy [7]

Answer:

After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light on the slab. As rays of all colours emerge in the same direction (of incidence of white light), hence there is no dispersion, but only lateral displacement.

6 0

2 years ago

Do you believe that a patient with late-stage Alzheimer's

strojnjashka [21]

The surgery would not be a hip replacement but would be resetting the broken bone with pins ad wires at late-stage Alzheimer's disease.

Older adults who have surgery with well-known anesthesia can also enjoy a modest acceleration of cognitive decline, even years later. but there may be no proof of a hyperlink to Alzheimer's disease, in step with new research from Mayo sanatorium.

Older adults who have surgical treatment with fashionable anesthesia can also experience a modest acceleration of cognitive decline, even years later. but there's no evidence of a link to Alzheimer's sickness, according to new research from Mayo sanatorium. most hip fractures require surgical treatment, generally within one of damage. hardly ever, hip fractures can be handled without surgical operation, usually in patients who may be too unwell or in a small group of patients that have recovery, non-displaced fractures that have been diagnosed weeks after injury.

Learn more about Alzheimer's disease here:-brainly.com/question/27414232

#SPJ9

6 0

2 years ago