Ask question

Ask question

All categories

3 years ago

7

Ms. Terry Novel is driving down the highway at 26 m/s when the driver sees the light ahead turn yellow. It takes the driver 0.3

s to react and the maximum braking acceleration of her car is 5.3 m/s2. If the light stays yellow for a total of 4 seconds, how far does she travel in this time?

1 answer:

Ket [755]3 years ago

7 0

Answer:

67.8 m.

Explanation:

For 0.3 sec which is the response time , he will keep on moving with velocity

undiminished or at 26 m/s .

Distance travelled during this period

= 26 x .3 =7.8 m

For rest of the time ie during 4 - .3 = 3.7 s , he decelerates with deceleration of 5.3 ms⁻² and initial velocity of 26 m/s

s = u t - 1/2 a t²

s = 26 x 3.7 - .5 x 5.3 x 3.7 x 3.7

= 96.2 - 36.28

= 60 m approx.

Total distance travelled

=60 + 7.8 = 67.8 m.

You might be interested in

Water being turned into ice cubes in a freezer is an example of _____.

Gekata [30.6K]

Answer:

a physical change

Explanation:

after the water turns to ice, it will melt and became water again making which means it's reversible this being. a physical change

7 0

2 years ago

Read 2 more answers

On the Moon the acceleration due to gravity is about one sixth that on Earth. If a golfer on the Moon imparted the same initial

swat32

Explanation:

We know that that the range of the ball on the earth

$R_{earth}=\frac{v_o^2sin2\theta}{g_{earth}}$

therefore, range of the ball on moon

$R_{moon}=\frac{v_o^2sin2\theta}{g_{moon}}$

$R_{moon}=\frac{v_o^2sin2\theta}{g_{earth}/12}$

therefore,

$R_{moon}=6R_{earth}$

Therefore, the range of ball will be 6 times on the moon than that on earth

6 0

2 years ago

How did Galileo's observations of Jupiter and Venus support Copernicus's model?

Contact [7]

Before Copernicus most people were thinking that the Earth is at center of universe. In 1609 Galileo observed sky through his home made telescope.
He found 4 moons orbiting Jupiter..It was a proof that bodies are orbiting other planets and not earth alone. <span>He found the crescent shape of Venus through his telescope and this could happen only if Sun is at center.</span>

7 0

3 years ago

A wheel is rotating freely at angular speed 420 rev/min on a shaft whose rotational inertia is negligible. A second wheel, initi

Mashcka [7]

Answer:60 rev/min

Explanation:

Given

angular speed of first shaft $\omega _1=420\ rev/min$

Moment of inertia of second shaft is seven times times the rotational speed of the first i.e. If I is the moment of inertia of first wheel so moment of inertia of second is 7 I

As there is no external torque therefore angular momentum is conserved

$L_1=L_2$

$I_1\omega _1=I_2\omega _2$

$I\times (420)=7 I\times (\omega _2)$

$\omega _2=\frac{420}{7}$

$\omega _2=60\ rev/min$

8 0

3 years ago

A package is dropped from a helicopter moving upward at 15 m/s. If it takes 16.0 s before the package hits the ground, how high

Lelu [443]

Answer:

The package was released at a height of 1015.296 meters.

Explanation:

The package is dropped at an initial velocity different of zero, decelerated and later accelerated by gravity. Let assume that final height is equal to zero, the final height is given by the following equation of motion:

$y = y_{o} + v_{o}\cdot t + \frac{1}{2}\cdot g \cdot t^{2}$

Where:

$v_{o}$ - Initial velocity, measured in meters per second.

$y$ - Final height, measured in meters.

$y_{o}$ - Initial height, measured in meters.

$t$ - Time, measured in seconds.

$g$ - Gravitational constant, measured in meters per square second.

(Positive sign - Package is moving upward, Negative sign - Package is moving downward)

The initial height is now cleared:

$y_{o} = y - v_{o}\cdot t - \frac{1}{2}\cdot g \cdot t^{2}$

Given that $y = 0\,m$ , $v_{o} = 15\,\frac{m}{s}$ , $g = -9.807\,\frac{m}{s^{2}}$ and $t = 16\,s$ , the final height of the package is:

$y_{o} = 0\,m - \left(15\,\frac{m}{s} \right)\cdot (16\,s) - \frac{1}{2}\cdot \left(-9.807\,\frac{m}{s^{2}} \right) \cdot (16\,s)^{2}$

$y_{o} = 1015.296\,m$

The package was released at a height of 1015.296 meters.

7 0

3 years ago