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3 years ago

An object that is accelerating may be

1 answer:

8 0

The answer of this question is D. All of the above

Acceleration happen when an obeject change its velocity. It has nothing to do with speed.

The huge misconception about acceleration is when we thought it only aply if we increase our speed ( in a sport match, sportcaster often describe acceleration as an increase in players speed)

slower, faster, right , left, it does not matter, as long as that object change its velocity, it accelerates

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A 0.29 kg particle moves in an xy plane according to x(t) = - 19 + 1 t - 3 t3 and y(t) = 20 + 7 t - 9 t2, with x and y in meters

Artist 52 [7]

Answer:

Part a)

$F = 7.76 N$

Part b)

$\theta = -137.7 degree$

Part c)

$\theta = -127.7 degree$

Explanation:

As we know that acceleration is rate of change in velocity of the object

So here we know that

$x = -19 + t - 3t^3$

$y = 20 + 7t - 9t^2$

Part a)

differentiate x and y two times with respect to time to find the acceleration

$a_x = \frac{d^2}{dt^2}(-19 + t - 3t^3)$

$a_x = \frac{d}{dt}(0 +1 - 9t^2)$

$a_x = -18t$

$a_y = \frac{d^2}{dt^2}(20 + 7t - 9t^2)$

$a_y = \frac{d}{dt}(0 +7 - 18t)$

$a_y = -18$

Now the acceleration of the object is given as

$\vec a = (-18t)\hat i + (-18)\hat j$

at t= 1.1 s we have

$\vec a = -19.8 \hat i - 18 \hat j$

now the net force of the object is given as

$\vec F = m\vec a$

$\vec F = (0.29 kg)(-19.8 \hat i - 18 \hat j)$

$\vec F = -5.74 \hat i - 5.22 \hat j$

now magnitude of the force will be

$F = \sqrt{5.74^2 + 5.22^2} = 7.76 N$

Part b)

Direction of the force is given as

$tan\theta = \frac{F_y}{F_x}$

$tan\theta = \frac{-5.22}{-5.74}$

$\theta = -137.7 degree$

Part c)

For velocity of the particle we have

$v_x = \frac{dx}[dt}$

$v_x = (0 +1 - 9t^2)$

$v_y = \frac{dy}{dt}$

$v_y = (0 +7 - 18t)$

now at t = 1.1 s

$\vec v = -9.89\hat i - 12.8 \hat j$

now the direction of the velocity is given as

$\theta = tan^{-1}(\frac{v_y}{v_x})$

$\theta = tan^{-1}(\frac{-12.8}{-9.89})$

$\theta = -127.7 degree$

7 0

3 years ago

During a new moon, the moon is between the

mylen [45]

The moon is between the sun and earth.

The side where the light from the sun hits the moon is facing away from earth.

5 0

3 years ago

Which of these pollutants is transferred from soil to water by organic pesticides and fertilizer runoff from farms?

Sedbober [7]

I would say your answer to this question would be D

4 0

3 years ago

Read 2 more answers

Find the frequency of a wave of wavelength 2.5m and speed 400 m/s

Sedaia [141]

Answer:

The frequency of wave is 160Hz.

Explanation:

Given that the formula of speed is V = f×λ where V represents speed, f is frequency and λ is wavelength.

So first thing, you have to make frequency the subject by dividing wavelength on both sides :

$v = f \times λ \:$

$v \div λ = f \times λ \div λ$

$f = \frac{v}{λ}$

Next you have to substitute the value of v and f into the formula :

Let λ = 2.5m,

Let v = 400m/s,

$f = \frac{400}{2.5}$

$f = 160Hz$

7 0

3 years ago

He vector parts that add up to the resultant are called ____.

cupoosta [38]

1. Answer: components

A two dimensional vector can be divided into two parts called horizontal component and vertical component.

A three dimensional vector can be divided into three components: one along x-axis, one along y-axis and one along z-axis.

Hence, the vector parts that add up to the resultant are called components.

2. Answer: 5 miles.

The resultant distance along the straight line from the starting point to the end point would be the displacement.

The displacement would be equal to the magnitude of the hypotenuse formed in the right triangle.

Displacement, $d=\sqrt{4^2+3^2}=\sqrt{16+9}=\sqrt{25}=5 miles$

3. Answer: Scalar

A scalar quantity has only magnitude. For example, speed and distance are scalar quantities and can be normally added to find the total.

A vector quantity has both magnitude as well as direction. The components are summed according to vector addition rules. For example, velocity, acceleration, force etc.

5 0

3 years ago