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3 years ago

Hicham El Guerrouj of Morocco holds the world record in the 1500 m running race. He ran the final 400 m in a time of 51.9 s.

Physics

1 answer:

konstantin123 [22]3 years ago

5 0

Answer: His average speed in mph over the last 400 m is 7.7 m/s.

Explanation:

Given: Hicham El Guerrouj of Morocco holds the world record in the 1500 m running race. He ran the final 400 m in a time of 51.9 s.

We know that , speed = $\dfrac{distance}{time}$

Here , distance = 400m and time = 51.9 s

Then, speed = $\dfrac{400}{51.9}\approx7.7\ m/s$

Hence, his average speed in mph over the last 400 m is 7.7 m/s.

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Farmer Wilcox wants to reduce the wind velocity near his farm. He should _____.

IRISSAK [1]

Plant trees around the perimeter of his fields

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3 years ago

Read 2 more answers

What is the sprinters output at 2.0 s, 4.0 s and 6.0 s?

kari74 [83]

A 59 kg sprinter, starting from rest, runs 47 m in 7.0 s at constant acceleration.?

What is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s?

Instantaneous Power is the force times velocity

P = Fv

Because the acceleration is constant, the force will be constant as well

F = ma

P = mav

for constant acceleration, the velocity at each time is found using

v = at

P = ma(at) = ma²t

find the acceleration using kinematic equation

s = ½at²

a = 2s/t²

a = 2(47) / 7.0²

a = 1.918 m/s²

P(2.0) = 59(1.918²)2.0 = 434.25 W = 0.43 kW

P(4.0) = 59(1.918²)4.0 = 868.51 W = 0.87 kW

P(6.0) = 59(1.918²)6.0 = 1302.76 W = 1.3 kW

I hope this helped.

5 0

3 years ago

A Nichrome wire 44 cm long and 0.30 mm in diameter is connected to a 3.1 V flashlight battery. What is the electric field inside

Alexeev081 [22]

Answer:

7.05 Volts/m

Explanation:

L = length of the Nichrome wire = 44 cm = 0.44 m

V = Potential difference across the end of the wire = battery voltage = 3.1 Volts

E = magnitude of electric field inside the wire

Magnitude of electric field inside the wire is given as

$E = \frac{V}{L}$

Inserting the values

$E = \frac{3.1}{0.44}$

E = 7.05 Volts/m

4 0

3 years ago

Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion. True or False.

pychu [463]

Answer: false.

Explanation:

Doppler effect is caused to the relative motion of the source of light/sound with respect to the observer.

If the source is moving towards you, you will perceive the frequency to be larger (also called a blue shift), while if the wave is moving away, you will perceive the frequency to be smaller (also called a red shift).

Then the statement:

"Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion."

Is false

3 0

2 years ago

!WILL GIVE BRAINLIEST!

vazorg [7]

As per angular momentum conservation we can say

$L_i = L_f$

here we know that

$mv_1r_1 = mv_2r_2$

we know that

$v_1 = 1.1 m/s$

$r_1 = 0.6 m$

$v_2 = ?$

$r_2 = 0.15 m$

now from above equation

$2(1.1)(0.6) = 2(v_2)(0.15)$

$v_2 = \frac{(1.1)(0.6)}{0.15}$

$v_2 = 4.4 m/s$

so speed is 4.4 m/s

8 0

3 years ago