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3 years ago

Please helpp this is due in 10 minutes?!!!!

Physics

1 answer:

Sati [7]3 years ago

5 0

Answer:

1. at the top of the coaster.

2. at the bottom of the coaster.

3. when the car is moving

4. when the car is moving

Explanation:

there is the most amount if potential energy at the top, and the keast at the bottom.

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in an isolated system, two cars, each with a mass of 1,500 kg, collide. car 1 is initially at rest while car 2 is moving at 5 m/

kirza4 [7]

Answer:2.5 m/s

Explanation:

6 0

3 years ago

· A car moves at 12 m/s and coasts up a hill with a

Zigmanuir [339]

Explanation:

Given that,

Initial speed of a car, u = 12 m/s

Aceleration, a = -1.6 m/s²

(a) The displacement of car after 6 seconds is :

$d=ut+\dfrac{1}{2}at^2\\\\d=12\times 6+\dfrac{1}{2}\times (-1.6)\times 6^2\\\\d=43.2\ m$

(b) The displacement of the car after 9 seconds is :

$d=ut+\dfrac{1}{2}at^2\\\\d=12\times 9+\dfrac{1}{2}\times (-1.6)\times 9^2\\\\d=43.2\ m$

Hence, this is the required solution.

7 0

3 years ago

3. A concrete highway is built of slabs 12 m long (20o C). How wide should the expansion cracks between the slabs be (at 20o C)

lesantik [10]

Answer:

$\Delta x=2.304\times 10^{-2}\ m=2.304\ cm$ is the minimum gap between the slabs

Explanation:

Given:

length of the concrete highway, $l=12\ m$

coefficient of thermal expansion, $\alpha=12\times 10^{-6}\ ^{\circ}C^{-1}$

range of temperature variation, $(-30^{\circ}C\ to\ 50^{\circ}C) \Rightarrow \Delta T=80^{\circ}C$

<u>Now form the equation of thermal expansion:</u>

$\Delta l=l\times \alpha\times \Delta T$

$\Delta l=12\times (12\times 10^{-6})\times 80$

$\Delta l=1.152\times 10^{-2}\ m$

Since each slab of the highway expands by the above length so the minimum gap between the slabs to prevent buckling:

$\Delta x=2\times \Delta l$

$\Delta x=2\times( 1.152\times 10^{-2})$

$\Delta x=2.304\times 10^{-2}\ m=2.304\ cm$ is the minimum gap between the slabs

4 0

3 years ago

2. Jenny picks up a guitar and strums. If the sound from the string emanates out at 440 Hz,

erik [133]

Answer:

6.8×10^6 m

Explanation:

f = velocity of light/ wavelength

440= 3×10^8 / wavelength

wavelength = 3×10^7/ 44

= 6.8×10^6 m

7 0

3 years ago

A truck speeds up from velocity of 6m/s to 14m/s in 4 seconds. what is the trucks acceleration?

Tanzania [10]

To calculate the acceleration of the truck, we use the equation of motion

$v = u + at$

Here, v is final velocity of the truck, u is initial velocity of truck, a is acceleration of the truck and t is time taken.

Given, u = 6 m/s, v = 14 m/s and t = 4 s.

Substituting these values in above equation, we get

$14 \ m/s = 6 \ m/s + a \times 4 \ s \\\\ a = \frac{14 \ m/s - 6 \ m/s}{ 4 \ s } = 2 \ m /s^2$ .

Thus, the truck acceleration is $2 \ m /s^2$

3 0

4 years ago