Ask question

Ask question

All categories

3 years ago

5

A car moving at 30 m/s slows uniformly to a speed of 10 m/s in a time of 5 s. Determine 1. The acceleration of the car. 2. The d

istance it moves in the third second.

1 answer:

ValentinkaMS [17]3 years ago

8 0

Answer:

Explanation:

Initial velocity , u = 30 m/s

final velocity , v = 10 m/s

time , t = 5 seconds

1. Acceleration = v - u / t

= 10 - 30 / 5

= -20 / 5

= <u><em>- 4 m/s</em></u>

You might be interested in

Compared with a force, a torque involves

ycow [4]

A rotational movement.

6 0

3 years ago

The picture below shows Lake Jackson in Florida

nikklg [1K]

The reason why Lake Jackson disappeared is A. opening of a sinkhole.
Pollution, high atmospheric temperature, and absorption of water by the land aren't enough for an entire lake to disappear, however, a sinkhole may contribute to that. There are two major depressions (sinkholes) in this lake in Florida, and they even have their own names - Porter Sink and Lime Sink.

4 0

3 years ago

Enrico Fermi (1901–1954) was a famous physicist who liked to pose what are now known as Fermi problems, in which several assumpt

Katarina [22]

Answer:

Explanation:

(a)

Since the earth is assumed to be a sphere.

Volume of atmosphere = volume of (earth +atm osphere) — volume of earth

$= \frac{4}{3}\pi(6400+ 50)^3 - \frac{4}{3}\pi (6400)
^3\\\\= \frac{4}{3}\pi(6192125000) km’^3\\= 2.6\times 10^{19} m^3$

Hence the volume of atmosphere is $2.6\times 10^{19} m^3$

(b)

Write the ideal gas equation as foll ows:

$PV = nRT\\\\n\frac{0.20atm\times 2.6\times10^{19} m^3}{0.08206L\, atm/mok\, K \times (15+273+15)K}\times \frac{1L}{10^{-3}m^3}\\\\= 2.20\times 10^{20} moles$

$no.\, of\, molecules = 2.20\times 10^{20} moles \times \frac{6.022\times10^{23}\,molecules}{1mole}= 13.3\times10^{43} molecules
$

Hence the required molecules is $13.3\times10^{43} molecules
$

(c)

Write the ideal gas equation as follows:

$PV =nRT
\\\\n=\frac{1.0 atm \times 0.5L
}{0.08206 L\, atm/mol\,K \times (37 +273.1 5)K} = 0.0196 moles$

$no.\, of\, molecules = 0.0196 moles \times\frac{6.022\times10^{23} molecules}
{Imole}= 1.2\times 10^{23} molecules$

Hence the required molecules in Caesar breath is $1.2\times 10^{23} molecules$

(d)

Volume fraction in Caesar last breath is as follows:

$Fraction,\, X =\frac{12\times 10 molecules}{13.3\times 10^{43} \,molecules}= 9.0\times 10\, molecule/air\, molecule}$

(e)

Since the volume capacity of the human body is 500 mL.

$Volume\, of\, Caesar\, nreath\, inhale\, is =\frac{ 12\times 10^{22}\, molecules}{breath}\times \frac{9.0\times10^{-23} molecule}{air\, molecule}\\\\= 1.08 molecule/breath$

5 0

3 years ago

A ball is thrown straight upward on the Moon. Is the maximum height it reaches less than, equal to, or greater than the maximum

IgorC [24]

The maximum height on moon is HIGHER than the maximum height on earth

6 0

3 years ago

Read 2 more answers

A mass accelerates uniformly when the resultant force on it:

WARRIOR [948]

F = ma
So if you want the "a" to stay constant (as it is then uniform acceleration), the F must also be constant to apply a constant force.

2 is the answer

3 0

3 years ago