An object orbiting the sun in a circle can be said to be.

A racecar driver is driving her car down the drag strip at 120 m/s. What is the shortest distance in which she can brake and sto

DaniilM [7]

Answer:

1034.78 m

Explanation:

The shortest distance is the displacement of the car from initial position to final position.

Displacement of body is given using Newton's equations of motion.

Given:

Initial velocity, $u = 120$ m/s

Final velocity, $v = 0$ m/s( As the car stops in its final position)

Coefficient of static friction, $\mu=0.71$

Acceleration due to gravity, $g=9.8\textrm{ } m/s^{2}$

Now, when brakes are applied, only friction acts on the body in a direction opposite to that of its motion.

The acceleration of the car when friction acts the stopping force is given as:

$a=- \mu g$ .

The acceleration is negative as it reduces the velocity of the motion and acts in the direction opposite to that of the motion.

Plug in 0.71 for $\mu$ and 9.8 m/s² for $g$ . Solve for $a$ .

So, $a=-0.71\times 9.8=-6.958\textrm{ }m/s^{2}$ .

Now, displacement of the car is given using the following equation of motion:

$v^{2}=u^{2} +2aS$

Here, $S$ is the displacement of the racing car.

Plug in 120 m/s for $u$ , 0 m/s for $v$ , -6.958 m/s² for $a$ . Solve for $S$ . This gives,

$0^{2} =(120)^{2}+2(-6.958)S\\13.916S=14400\\S=\frac{14400}{13.916}=1034.78\textrm{ m}$

Therefore, the shortest distance in which she can brake and stop is 1034.78 m.

5 0

4 years ago

Read 2 more answers

If energy is continually added to a gas, what will it likely become?

tamaranim1 [39]

The gas will remain a gas and the energy will be transformed into heat raising the temperature
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For a wave, what term is defined as the maximum height of a crest, or depth of a trough, relative to the normal level? for a wav

sammy [17]

The appropriate response is amplitude. Amplitude is the target estimation of the level of progress (positive or negative) in environmental weight (the pressure and rarefaction of air atoms) created by sound waves.

I hope the answer will help you.

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3 years ago

Which formula uses mass in the equation?

Naya [18.7K]

The mass can be calculated by dividing the net force acting on an object by the acceleration of the object. When talking about net force, we use the units kilogram meter per second squared. This is also known as a Newton. The units for acceleration is meters per seconds squared, and the units for mass are kilograms.

5 0

3 years ago

A man hits a ball and provides it with an initial velocity of 5.0 m/s on a rough horizontal surface. Due to the surface the ball

Alex777 [14]

Answer:

a) After 5.19 seconds dog catch the ball.

b) From the dog's initial position at 20.20 m dog catches the ball.

c) Speed of the ball when dog catches ball = 2.405 m/s

Speed of the dog when dog catches ball = 7.785 m/s

Explanation:

a) Let the time of catching be t.

We have equation of motion s = ut + 0.5 at²

Consider the motion of ball

Initial velocity, u = 5 m/s

Acceleration, a = -0.5 m/s²

Time, t = t

Substituting

s = 5 x t + 0.5 x -0.5 x t²

s = 5t - 0.25t²

Consider the motion of dog

Initial velocity, u = 0 m/s

Acceleration, a = 1.5 m/s²

Time, t = t

Substituting

s + 1 = 0 x t + 0.5 x 1.5 x t²

s = 0.75t²

If they catch up displacement of dog is 1 m more than displacement of ball.

That is

5t - 0.25t² + 1 = 0.75t²

t² - 5t -1 = 0

t = 5.19 or t = -0.19(not possible)

So after 5.19 seconds dog catch the ball.

b) Displacement of dog, s = 0.75t²

s = 0.75 x 5.19²

s = 20.20 m

From the dog's initial position at 20.20 m dog catches the ball.

c) We have equation of motion v = u + at

Consider the motion of ball

Initial velocity, u = 5 m/s

Acceleration, a = -0.5 m/s²

Time, t = 5.19 s

Substituting

v = 5 + -0.5 x 5.19 = 2.405 m/s

Speed of the ball when dog catches = 2.405 m/s

Consider the motion of dog

Initial velocity, u = 0 m/s

Acceleration, a = 1.5 m/s²

Time, t = 5.19 s

Substituting

v = 0 + 1.5 x 5.19 = 7.785 m/s

Speed of the dog when dog catches ball = 7.785 m/s

3 0

3 years ago