Math problem help!!!!!!!!?

Question

1)There are approximately 250 million passenger vehicles registered in the United States. Assume that the battery in the average vehicle stores 440 watt-hours (Wh) of energy. Estimate (in gigawatt-hours) the total energy stored in US passenger vehicles
2) A hand-held video player displays 320x240 picture elements in each frame of the video. Each pixel requires 2 bytes of memory. Videos are displayed at a rate of 30 frames per second. How many minute of video will fit in a 30 gigabyte memory?

Answer 1

Hi,

1) Since there are 440watt-hours for each passenger vehicle, while we have 250 million passenger vehicles, we can get the total energy stored by multiplying both figure, so that the value is:

440 * 250,000,000 Watt-hours
= 110,000,000,000 Watt - hours

However, we want the value to be in Gigawatt-hours.

1 Gigawatt = 1,000,000,000 watt

Therefore, the answer to this is

= 110,000,000,000 Watt - hours
= 110 GigaWatt - hours

======================
Answer = 110 GigaWatt - hours
======================

2.

Wow, this will be a bit long to explain, but here goes :)

Just for your information, pixel stands for 'picture elements'
From the data, we can obtain the total amount of pixels in each frame of the video, that is:

320 x 240 = 134,400 pixels

Now, since each pixel requires 2 bytes of memory, and we have 134,400 pixels, therefore the amount of memory for a frame of video is

134,400 * 2
= 268,800 bytememory / frame.

Thus, how many frames will be displayed in a 30gigabyte memory?

We can just divide this, so that:

30,000,000,000 / 268,800
= 111607.143 frames
= 111607 frames -- rounding down

Next, we have to find the time to display 111,607 frames.
We have the information that "Videos are displayed at a rate of 30 frames per second".

Therefore, the total amount of seconds to display 111,607 frames is:

111607/30
= 3720.233 seconds
= 3720 seconds (rounding down)

But we want the answer in minute.
Therefore,

3720 seconds
= 3720/60 minutes
= 62 minutes.

===================
Answer: = 62 minutes
===================

Hope this helps

Kind regard,
Ryonn

Answer 2

1.
250 x 10 ^6 vehicles x 440 watt-hr / vehicle x 10^-6 gigawatt-hr / watt hour
you can do the calculation from here

2.
30 GB/ [(320 x 240 pixels / frame x 2B/pixel x 10^-6GB/B x 30 frames/sec x 60 sec/min)]

remember to treat units as algebra and work from there

Understand what I did - and all other problems will fall into place

Answer 3

im hope im correct
1.(11 gigawatts)
2.(3.616)gigabytes