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2 years ago

A sprinter accelerates from rest to a velocity of 12m/s in the first 6 seconds of the 100 meter dash .

Physics

1 answer:

GREYUIT [131]2 years ago

5 0

Answer:

a) 36 m

b) 64 m

Explanation:

Given:

v₀ = 0 m/2

v = 12 m/s

t = 6 s

Find: Δx

Δx = ½ (v + v₀) t

Δx = ½ (12 m/s + 0 m/s) (6 s)

Δx = 36 m

The track is 100 m, so the sprinter still has to run another 64 m.

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One of the great dangers to mountain climbers is an avalanche, in which a large mass of snow and ice breaks loose and goes on an

sammy [17]

Answer:

Explanation:

The acceleration of an object down a slope (neglecting friction, µ = 0) is:

a = g × sin θ

Where,

g is the acceleration due to gravity and θ is the angle of the slope.

a = (9.8 × sin (21.5º)

= 3.592 m/s²

Using equations of motion,

S = ut + 1/2at²

Since, u = 0,

S = 1/2at²

347 = 1/2 × (3.592)t²

t² = 193.21

= sqrt(193.21)

= 13.9 s.

5 0

2 years ago

A man stands on his balcony, 130 feet above the ground. He looks at the ground, with his sight line forming an angle of 70° with

jenyasd209 [6]

Answer:

d = 380 feet

Explanation:

Height of man = perpendicular= 130 feet

Angle of depression = ∅ = 70 °

distance to bus stop from man = hypotenuse = d = 130 sec∅

As sec ∅ = 1 / cos∅

so d = 130 sec∅ or d = 130 / cos∅

d = 130 / cos(70°)

d = 380 feet

8 0

2 years ago

Mary takes 6.0 seconds to run up a flight of stairs that is 102 meters long. if mary's weight is 87 newtons, what power has mary

pentagon [3]

Thank you for posting your question here at brainly. I hope the answer will help. Below are the choices that can be found elsewhere:

A. 1.5 * 10^3 Watts
B. 7.3 * 10^2 Watts
C. 3.5 * 10^2 Watts
D. 2.5 * 10^2 Watts

Work = force*displacement = 10^2*87 = 8,700 joule
Power = work/time = 8,700/6 = 1.45*10^3 (rounded up to 1.5 kw). The answer is A.

3 0

2 years ago

Read 2 more answers

A carbon-dioxide laser emits infrared light with a wavelength of 10.6 μm. What is the length of a tube that will oscillate in th

alex41 [277]

Answer:

The length of a tube and number of rounds are 0.848 m and $1.77\times10^{8}\ trip\ per\ second$ .

Explanation:

Given that,

Wavelength $\lambda= 10.6\mu m$

m = 160000

We need to calculate the length

Using formula of wavelength

Laser tube behave like closed pipe

$m\dfrac{\lambda}{2}=L$

$L=160000\times\dfrac{10.6\times10^{-6}}{2}$

$L=0.848\ m$

Distance traveled by pulse of light in one back and fourth trip

$d=2L$

$d=2\times0.848$

$d=1.696\ m$

We need to calculate the time

Using formula for time

$t = \dfrac{d}{c}$

$t=\dfrac{1.696}{3\times10^{8}}$

$t=5.653\times10^{-9}\ s$

We need to calculate the number of round

Using formula of number of round

$N=\dfrac{1}{t}$

$N= \dfrac{1}{5.653\times10^{-9}}$

$N=1.77\times10^{8}\ trip\ per\ second$

Hence, The length of a tube and number of rounds are 0.848 m and $1.77\times10^{8}\ trip\ per\ second$ .

7 0

2 years ago

A bee wants to fly to a flower located due North of the hive on a windy day. The wind blows from East to West at speed 6.68 m/s.

Aleonysh [2.5K]

Answer: $53.31\°$ East of North

Explanation:

We have the following data:

Speed of the wind from East to West: $6.68 m/s$

Speed of the bee relative to the air: $8.33 m/s$

If we graph these speeds (which in fact are velocities because are vectors) in a vector diagram, we will have a right triangle in which the airspeed of the bee (its speed relative to te air) is the hypotense and the two sides of the triangle will be the Speed of the wind from East to West (in the horintal part) and the speed due North relative to the ground (in the vertical part).

Now, we need to find the direction the bee should fly directly to the flower (due North):

$sin \theta=\frac{Windspeed-from-East-to-West}{Speed-bee-relative-to-air}$

$sin \theta=\frac{6.68 m/s}{8.33 m/s}$

Clearing $\theta$ :

$\theta=sin^{-1} (\frac{6.68 m/s}{8.33 m/s})$

$\theta=53.31\°$

6 0

2 years ago