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3 years ago

A lorry pulls forward after initially being stationary, it takes the lorry 80m to reach a speed of

Physics

1 answer:

____ [38]3 years ago

6 0

Answer:

a=f/m

Explanation:

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tourist travels 1500 miles using two planes. The second plane averages 50 miles per hour faster than the first plane. The touris

Genrish500 [490]

Answer

given,

tourist travels = 1500 miles

second plane averages 50 miles per hour faster than the first plane.

x = y + 50

The tourist uses the slower plane for the first 500 and the faster plane for the next 1000 miles.

total flying time = 6.5 hours

$\dfrac{500}{y} + \dfrac{1000}{x} = 6.5$

$\dfrac{500}{y} + \dfrac{1000}{y + 50} = 6.5$

$\dfrac{500(50 + y)+ 1000 y}{y(y + 50)} = 6.5$

$25000 + 600 y = 6.5 y^2 + 325 y$

$6.5 y^2 - 275 y - 25000 = 0$

on solving equation

y = 86.67 mile/hr

x = 86.67 + 50

x = 136.67 mile/hr

8 0

3 years ago

How much heat is gained by 1.0 gram of iron when its heated 15 degrees celsius

Firdavs [7]

Q = mass water x specific heat water x delta T.
<span>714,000 = mass water x specific heat water x 30.
Substitute specific heat water and solve for mass water.</span>

3 0

3 years ago

Which of the following describes wavelength?

blagie [28]

D. The number of wave that pass a point in a given amount of time

3 0

4 years ago

For no apparent reason, a poodle is running at a constant speed of 5.00 m/s in a circle with radius 2.9 m . Let v⃗ 1 be the velo

Nostrana [21]

At a constant speed of 5.00 m/s, the speed at which the poodle completes a full revolution is

$\left(5.00\,\dfrac{\mathrm m}{\mathrm s}\right)\left(\dfrac{1\,\mathrm{rev}}{2\pi(2.9\,\mathrm m)}\right)\approx0.2744\,\dfrac{\mathrm{rev}}{\mathrm s}$

so that its period is $T=3.644\,\frac{\mathrm s}{\mathrm{rev}}$ (where 1 revolution corresponds exactly to 360 degrees). We use this to determine how much of the circular path the poodle traverses in each given time interval with duration $\Delta t$ . Denote by $\theta$ the angle between the velocity vectors (same as the angle subtended by the arc the poodle traverses), then

$\Delta t=0.4\,\mathrm s\implies\dfrac{3.644\,\mathrm s}{360^\circ}=\dfrac{0.4\,\mathrm s}\theta\implies\theta\approx39.56^\circ$

$\Delta t=0.2\,\mathrm s\implies\dfrac{3.644\,\mathrm s}{360^\circ}=\dfrac{0.2\,\mathrm s}\theta\implies\theta\approx19.78^\circ$

$\Delta t=7\times10^{-2}\,\mathrm s\implies\dfrac{3.644\,\mathrm s}{360^\circ}=\dfrac{7\times10^{-2}\,\mathrm s}\theta\implies\theta\approx6.923^\circ$

We can then compute the magnitude of the velocity vector differences $\Delta\vec v$ for each time interval by using the law of cosines:

$|\Delta\vec v|^2=|\vec v_1|^2+|\vec v_2|^2-2|\vec v_1||\vec v_2|\cos\theta$

$\implies|\Delta\vec v|=\begin{cases}3.384\,\frac{\mathrm m}{\mathrm s}&\text{for }\Delta t=0.4\,\mathrm s\\1.718\,\frac{\mathrm m}{\mathrm s}&\text{for }\Delta t=0.2\,\mathrm s\\0.6038\,\frac{\mathrm m}{\mathrm s}&\text{for }\Delta t=7\times10^{-2}\,\mathrm s\end{cases}$

and in turn we find the magnitude of the average acceleration vectors to be

$\implies|\vec a|=\begin{cases}8.460\,\frac{\mathrm m}{\mathrm s^2}&\text{for }\Delta t=0.4\,\mathrm s\\8.588\,\frac{\mathrm m}{\mathrm s^2}&\text{for }\Delta t=0.2\,\mathrm s\\8.625\,\frac{\mathrm m}{\mathrm s^2}&\text{for }\Delta t=7\times10^{-2}\,\mathrm s\end{cases}$

So that takes care of parts A, C, and E. Unfortunately, without knowing the poodle's starting position, it's impossible to tell precisely in what directions each average acceleration vector points.

5 0

3 years ago

If red light hits a red filter, what kind of light comes through the filter?

Roman55 [17]

A. red, is the correct answer. A red filter only lets red light through, whether white or red light passes through it.
Hope this helps, and have a great day!

8 0

4 years ago