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2 years ago

An object is released from height of 17m. The object will hit the ground approximately in

1 answer:

5 0

$\text{Given that,}\\\\\text{Height, h = 17 m}\\\\\\\text{We know that,}\\\\h = v_0t + \dfrac 12 gt^2\\\\\implies h = \dfrac 12 gt^2\\\\\implies t^2 = \dfrac{2h}g\\\\\implies t =\sqrt{\dfrac{2h}g} = \sqrt{\dfrac{2(17)}{9.81}} = 1.87 ~ \text{sec}$

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The wavelength of 10^15-Hz light is:

Vanyuwa [196]

Answer:

D.300nm

Explanation:

Wavelength = Speed of light / Frequency of light.....

where the speed of light is...(3 × 10^8)

Wavelength = (3 × 10^8)/(1 × 10^15)

Wavelength = 3 × 10^-7

;Wavelength = 300 × 10^-9

Hence its....300 nm

5 0

2 years ago

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Zarrin [17]

Answer:

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2 years ago

Suppose that in a lightning flash the potential difference between a cloud and the ground is 0.96×109 V and the quantity of char

Dvinal [7]

(a) $2.98\cdot 10^{10} J$

The change in energy of the transferred charge is given by:

$\Delta U = q \Delta V$

where

q is the charge transferred

$\Delta V$ is the potential difference between the ground and the clouds

Here we have

$q=31 C$

$\Delta V = 0.96\cdot 10^9 V$

So the change in energy is

$\Delta U = (31 C)(0.96\cdot 10^9 V)=2.98\cdot 10^{10} J$

(b) 7921 m/s

If the energy released is used to accelerate the car from rest, than its final kinetic energy would be

$K=\frac{1}{2}mv^2$

where

m = 950 kg is the mass of the car

v is the final speed of the car

Here the energy given to the car is

$K=2.98\cdot 10^{10} J$

Therefore by re-arranging the equation, we find the final speed of the car:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(2.98\cdot 10^{10})}{950}}=7921 m/s$

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3 years ago

Why do you think glass bottles keep water cold longer?

Nina [5.8K]

Because glass is not a good heat conductor. What it means is that heat isn't transfered through its structure as quickly as it would with metal, for instance. Because heat can't penetrate glass as quickly, the contents stay at the same temperature for longer.

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2 years ago

for a body moving in a straight line / its distance and displacement can be same. justify with an example?

Tema [17]

The distance of an object is the total distance it travels, while the displacement of the object is how far away the object is from the starting point.

Because the body is moving in a STRAIGHT line, that means it does not change directions, therefore when the body gets to the destination, the total distance will be the same as the displacement. If the body were to change directions, then the magnitude of the vectors will need to be added up and calculated.

For example, let's say you are walking to your friends house directly across the street from your house. All you need to do is walk in a strsight line from the front of your house and you will get to your friends house. The distance and displacement will be the same.

Now if your friend lived right across the street, but 5 houses down, and you cross the street directly from your house then turn in another direction and walk straight, then the distance in this case will quite likely be greater than the displacement because the displacement is the distance from your house to your friends house when measured diagonally.

6 0

2 years ago