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3 years ago

an automobile is traveling 65km/h the brakes decelerate it at a rate of -6.0 m/s^2 how long will it take to stop the car?

Physics

1 answer:

joja [24]3 years ago

6 0

Explanation:

It is given that,

Initial speed of the automobile, u = 65 km/hr =

Final speed of the automobile, v = 0

Deceleration of the automobile, $a=-6\ m/s^2$

We need to find the distance covered by the car as it comes to rest. It can be calculated using third equation of motion as :

$v^2-u^2=2ax$

$a=\dfrac{v^2-u^2}{2x}$

$a=\dfrac{0-(18.05)^2}{2\times (-6)}$

$a=27.15\ m/s^2$

So, the acceleration of the car is $27.15\ m/s^2$ . Hence, this is the required solution.

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A car travels at a constant rate for 100 miles going due west for one hour. Then it travels at a constant rate for another 75 mi

nirvana33 [79]

Answer:

C. 100 mph west

Explanation:

Average velocity is total displacement over total time. During the first hour, the average velocity is:

v_avg = 100 mi / 1 hr

v_avg = 100 mph west

Since the velocity is constant, the instantaneous velocity at any time equals the average velocity.

v = v_avg

v = 100 mph west

7 0

4 years ago

The mass of Tesla Model S is 2000 kg and its engine produces

yulyashka [42]

Answer:

The ratio of the power generated by the engines are $\dfrac{2}{3}$

(b) is correct option.

Explanation:

Given that,

Mass of Tesla = 2000 Kg

Torque = 400 Nm

Mass of Mercedes = 1.5 M Tesla

The Benz engine produces 50% more torque than the Tesla.

We need to calculate the power generated by the engines 6 seconds after a start from rest

Using formula of power

$P=F\cdot v$

We know that,

$v=at$

$v=\dfrac{F}{m}t$

$v=\dfrac{\tau}{mr}t$

Put the value of F and v in equation (I)

$P=\dfrac{\tau}{r}\times\dfrac{\tau}{mr}t$

$P=\dfrac{\tau^2t}{mr^2}$

Here, r and t are same for both bodies.

$P\propto\dfrac{\tau^2}{m}$

We need to calculate the ratio of the power generated by the engines

Using formula of power

$\dfrac{P_{T}}{P_{B}}=\dfrac{\tau_{T}^2}{m_{T}}\times\dfrac{m_{B}}{\tau_{B}}$

Put the value into the formula

$\dfrac{P_{T}}{P_{B}}=\dfrac{400^2}{2000}\times\dfrac{3000}{600^2}$

$\dfrac{P_{T}}{P_{B}}=\dfrac{2}{3}$

Hence, The ratio of the power generated by the engines are $\dfrac{2}{3}$

3 0

3 years ago

John doesn't think that skepticism should play an important role in the scientific process. He says that skepticism interferes w

Sergio039 [100]

Answer: it is incorrect because skepticism helps scientists recognize when ideas are not supported by evidence.

Explanation:

Skepticism is simply the understanding that there can be uncertainty when it comes to knowledge in certain areas.

From the question, we are informed that John doesn't think that skepticism should play an important role in the scientific process and that he says that skepticism interferes with scientific consensus.

The statement that best describes John's conclusion is that it is incorrect because skepticism helps scientists recognize when ideas are not supported by evidence.

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3 years ago

Where do you find electromagnetic waves on earth? what are some everyday uses?

Norma-Jean [14]

Answer:

Radio waves are used for communications and radar. Microwaves are used to cook your food. Infrared waves are used in remote controls and are emitted from all warm objects, allowing them to be used to create heat-sensitive cameras.

Explanation:

Basically electromagnetic waves can be found in your everyday life.

8 0

3 years ago

Read 2 more answers

9.58 A spring of equilibrium length L1 and spring constant k1 hangs from the ceiling. Mass m1 is suspended from its lower end. T

andrey2020 [161]

Answer:

The distance of m2 from the ceiling is L1 +L2 + m1g/k1 + m2g/k1 + m2g/k2.

See attachment below for full solution

Explanation:

This is so because the the attached mass m1 on the spring causes the first spring to stretch by a distance of m1g/k1 (hookes law). This plus the equilibrium lengtb of the spring gives the position of the mass m1 from the ceiling. The second mass mass m2 causes both springs 1 and 2 to stretch by an amout proportional to its weight just like above. The respective stretchings are m2g/k1 for spring 1 and m2g/k2 for spring 2. These plus the position of m1 and the equilibrium length of spring 2 L2 gives the distance of L2 from the ceiling.

4 0

4 years ago