All categories

2 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]2 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.

You might be interested in

If the newton is the product of kilograms and meters/second2 what units comprise the pound?

Kobotan [32]

Answer:

Pound is the product of slug and foot/square second.

Explanation:

We are given that

Force=1 N

1N= $1kg\times ms^{-2}$

We have to find the units comprise the pound.

Force=1 Pound

Mass=Slug

Acceleration= $ft/s^2$

Therefore,

1 pound= $1 slug\times fts^{-2}$

Therefore, we can write as 1 pound is equal to the product of slug and ft/square second.

Hence, pound is the product of slug and foot/square second.

6 0

2 years ago

A motor boat is traveling east with a velocity of 7.3 meter/seconds. Its experiences a current of 0.34 meters/seconds from the e

andreev551 [17]

Since they're going in the same direction, just add the velocities together.

7.3 m/s + 0.34 m/s = 7.64m/s

3 0

2 years ago

Read 2 more answers

A river flows with a uniform velocity vr. A person in a motorboat travels 1.22 km upstream, at which time she passes a log float

storchak [24]

Answer:

t ’= $\frac{1450}{0.6499 + 2 v_r}$ , v_r = 1 m/s t ’= 547.19 s

Explanation:

This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.

By the time the boat goes up the river

v_b - v_r = d / t

By the time the boat goes down the river

v_b + v_r = d '/ t'

let's subtract the equations

2 v_r = d ’/ t’ - d / t

d ’/ t’ = 2v_r + d / t

$t' = \frac{d'}{ \frac{d}{t}+ 2 v_r }$

In the exercise they tell us

d = 1.22 +1.45 = 2.67 km= 2.67 10³ m

d ’= 1.45 km= 1.45 1.³ m

at time t = 69.1 min (60 s / 1min) = 4146 s

the speed of river is v_r

t ’= $\frac{1.45 \ 10^3}{ \frac{ 2670}{4146} \ + 2 \ v_r}$

t ’= $\frac{1450}{0.6499 + 2 v_r}$

In order to complete the calculation, we must assume a river speed

v_r = 1 m / s

let's calculate

t ’= $\frac{ 1450}{ 0.6499 + 2 \ 1}$

t ’= 547.19 s

8 0

2 years ago

Two wheels are identical but wheel b is spinning with twice the angular speed of wheel

Murljashka [212]

<span>If two wheels are exactly the same but spin at different speeds, wheel b is twice te speed of wheel a, it is possible to find the ratio of the magnitude of radial acceleration at a singular point of the rim on wheel be to the spot is four.</span>

6 0

2 years ago

Three different planet-star systems, which are far apart from one another, are shown above. The masses of the planets are much l

alex41 [277]

a) 4F0

b) Speed of planet B is the same as speed of planet A

Speed of planet C is twice the speed of planet A

Explanation:

The magnitude of the gravitational force between two objects is given by the formula

$F=G\frac{m_1 m_2}{r^2}$