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2 years ago

An athlete practicing for a track meet ran 400 meter in 50 seconds. What was his average speed?

Physics

1 answer:

sattari [20]2 years ago

7 0

Speed= Distance ÷ time

Speed= 400 ÷ 50 =8 m/s

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The Hi line of the Balmer series is emitted in the transition from n = 3 to n = 2. Compute the wavelength of this line for l H a

irina1246 [14]

Answer:

$\lambda=550\ nm$

Explanation:

The Hi line of the Balmer series is emitted in the transition from n = 3 to n = 2 i.e. $n_i=3$ and $n_f=2$

The wavelength of Hi line of the Balmer series is given by :

$\dfrac{1}{\lambda}=R(\dfrac{1}{n_f}-\dfrac{1}{n_i})$

$\dfrac{1}{\lambda}=1.09\times 10^7\times (\dfrac{1}{2}-\dfrac{1}{3})$

$\lambda=5.50\times 10^{-7}\ m$

$\lambda=550\ nm$

So, the wavelength for this line is 550 nm. Hence, this is the required solution.

6 0

3 years ago

Two insulated current-carrying wires (wire 1 and wire 2) are bound together with wire ties to form a two-wire unit. The wires ar

AysviL [449]

Answer:

I'm not sure, My best friend knows, but I don't...

Explanation:

I'm sorry :)

7 0

2 years ago

A factory emits pollutants at a rate of 25 g/s. The factory is located between two mountain ranges resulting in an effective val

Lostsunrise [7]

Answer:

$1.25\ \mu\text{g/m}^3$

Explanation:

v = Velocity of the breeze = 4 m/s

w = Width of the valley = 5000 m

h = Height of the valley = 1000 m

Volumetric flow rate is given by

$\dot{V}=vwh\\\Rightarrow \dot{V}=4\times 5000\times 1000\\\Rightarrow \dot{V}=2\times10^{7}\ \text{m}^3/\text{s}$

$\dot{m}$ = Mass flow rate of pollutant = 25 g/s = $25\times 10^6\ \mu\text{g/s}$

Concentration is given by

$C=\dfrac{\dot{m}}{\dot{V}}\\\Rightarrow C=\dfrac{25\times 10^6}{2\times 10^7}\\\Rightarrow C=1.25\ \mu\text{g/m}^3$

The steady state concentration of pollutants in the valley, is $1.25\ \mu\text{g/m}^3$ .

6 0

2 years ago

a load of 400 Newton is lifted by a first class lever in which the load is at the distance of 20 cm and the effort is at the dis

Len [333]

Answer:

solution,
Given
load =400N
ld=0.2m
ed=0.6m
effort =150N

Explanation:

efficiency =output work/input work ×100%

l×ld/e×ed×100%

400×0.2/150×0.6×100%

80/90×100%

88.89%ans

7 0

2 years ago

A girl and boy pull in opposite directions on a stuffed animal. The girl exerts a force of 3.5 N. The mass of the stuffed animal

givi [52]

I'm gonna have to assume the girl is on the right side and boy on left.
The net force is the sum of all forces on an object (includes negatives).
Let's say the force of the boy is variable b. Use the formula F = ma.

b + 3.5 = 0.2(2.5)

This is now simple algebra. Solve to get that the boty is exerting a force of -3N to the left.

5 0

3 years ago

Read 2 more answers