An object hits the ground travelling at 8 km/hr. It is brought to rest in 0.4 seconds. What is its

A girl operates a radio-controlled model car in a vacant parking lot. the girl’s position is at the origin of the xy coordinate

Drupady [299]

The position at time t is
x(t) = 0.5t³ - 3t² + 3t + 2

When the velocity is zero, the derivative of x with respect to t is zero. That is,
x' = 1.5t² - 6t + 3 = 0
or
t² - 4t + 2 = 0

Solve with the quadratic formula.
t = (1/2) [ 4 +/- √(16 - 8)] = 3.4142 or 0.5858 s

When t =0.5858 s, the position is
x = 0.5(0.5858³) - 3(0.5858²) + 3(0.5858) + 2 = 2.828 m
When t=3.4142 s, the position is
x = 0.5(3.4142³) - 3(3.4142²) + 3(3.4142) + 2 = -2.828 m
Reject the negative answer.

Answer:
The velocity is zero when t = 0.586 s, and the distance is 2.83 m

When the acceleration is zero, the second derivative of x with respect to t is zero. That is,
3t - 6 = 0
t = 2
The distance traveled is
x = 0.5(2³) - 3(2²) + 3(2) + 2 = 0

Answer:
When the acceleration is zero, t = 2 s, and the distance traveled is zero.

7 0

4 years ago

True or false the refraction of a wave is how many wavelengths pass a fixed point each second

Ksenya-84 [330]

False. That description fits the wave's 'frequency'.
It has nothing to do with refraction.

8 0

3 years ago

Read 2 more answers

What happens to a light if the switch is turned off in the circuit?

lukranit [14]

In a parallel circuit nothing happens. All the other lights stay on but if it was a series circuit ALL the lights would turn off at one time.

If there is an ABCD question I can answer that but I wasn't sure so I just said this

Hope it is helpful :)

6 0

3 years ago

Sound source A is located at x = 0, y = 0, and sound source B is located at x = 0, y = 2.3 m. The two sources radiate coherently

Oliga [24]

Answer:

Solution is given in the attachments

4 0

3 years ago

The tape in a videotape cassette has a total

xxMikexx [17]

Answer:

$w=19.76 \ rad/s$

Explanation:

<u>Circular Motion </u>

Suppose there is an object describing a circle of radius r around a fixed point. If the relation between the angle of rotation by the time taken is constant, then the angular speed is also constant. If that relation increases or decreases at a constant rate, the angular speed is given by:

$w=w_o+\alpha \ t$

Where $\alpha$ is the angular acceleration and t is the time. If the object was instantly released from the circular path, it would have a tangent speed of:

$\displaystyle v_t=w.r$

We have two reels: one loaded with the tape to play and the other one empty and starting to fill with tape. They both rotate at different angular speeds, one is increasing and the other is decreasing as the tape goes from one to the other. We'll assume the tangent speed is constant for both (so the tape can play correctly). Let's call $w_1$ the angular speed of the loaded reel and $w_2$ that from the empty reel. We have