I need help with number 8

In the diagram below, point A is southwest of point B. Jaleh walks for 400 seconds along path 1, going from point A to point B.

timama [110]

Answer:

C

Explanation:

velocity = displacement (m) / change of time (s)

velocity = (400 + 300) / (100 + 400)

velocity = 1.4 m/s

4 0

2 years ago

Read 2 more answers

A car is initially traveling at 17 m/s when the driver steps down hard on the gas pedal

ddd [48]

Answer:

29 m/s

Explanation:

Acceleration is the rate of change of velocity, i.e, the change in velocity per unit time.

The driver made the car to accelerate at 3 m/s^2. That means than in every second the velocity of the car increased by 3 m/s. Therefore in four seconds its velocity would increase by 3m/s x 4 = 12m/s. Starting with an initial velocity of 17 m/s the final velocity would be 17 m/s + 12 m/s = 29 m/s.

6 0

3 years ago

A house at the bottom of a hill is fed by a full tank of water 5m deep and connected to the house by a pipe that is 110m long at

yawa3891 [41]

Answer:

a) $p=964178.7\ Pa$

b) $h=98.2853\ m$

Explanation:

Given;

depth of the water-tank, $d=5\ m$

length of the pipe, $l=110\ m$

inclination of the pipe from the horizontal, $\theta =58^{\circ}$

a)

Now the effective vertical height of the water column from the free surface of the water to the bottom of the pipe at house:

$h=d+l.\sin\theta$

$h=5+110\sin58$

$h=98.2853\ m$

Now the pressure due to effective water head:

$p=\rho.g.h$

where:

$\rho=$ density of the liquid, here water

$g=$ acceleration due to gravity

$h=$ height of the liquid column

$p=1000\times9.81\times 98.2853$

$p=964178.7\ Pa$

b)

Now the height of water corresponding to this pressure will be the same as the effective water head by the law of conservation of energy.

$h=98.2853\ m$

6 0

3 years ago

Why does a person while firing a bullethold the gun tightly to his shoulders?

Taya2010 [7]

Answer:

here's your ans......

6 0

3 years ago

At noon, ship A is 110 km west of ship B. Ship A is sailing east at 20 km/h and ship B is sailing north at 15 km/h. How fast is

Katyanochek1 [597]

Answer:

$4.47\ \text{km/h}$

Explanation:

$\dfrac{da}{dt}$ = Rate at which the distance between A and starting point of B is changing = -20 km/h

$\dfrac{db}{dt}$ = Rate at which the distance of B is changing = 15 km/h

$\dfrac{dc}{dt}$ = Rate at which the distance between A and B is changing

Time after which the rate at which the distance between A and B is changing is 4 hours

Distance covered by A in 4 hours = $20\times 4=80\ \text{km}$

a = Distance remaining to the start point of B = $110-80=30\ \text{km}$

b = Distance covered by B in 4 hours = $15\times 4=60\ \text{km}$

Distance between A and B after 4 hours

$c=\sqrt{a^2+b^2}\\\Rightarrow c=\sqrt{30^2+60^2}\\\Rightarrow c=67.08\ \text{km}$

$c^2=a^2+b^2$

Differentiating with respect to time we get

$c\dfrac{dc}{dt}=a\dfrac{da}{dt}+b\dfrac{db}{dt}\\\Rightarrow \dfrac{dc}{dt}=\dfrac{a\dfrac{da}{dt}+b\dfrac{db}{dt}}{c}\\\Rightarrow \dfrac{dc}{dt}=\dfrac{30\times -20+60\times 15}{67.08}\\\Rightarrow \dfrac{dc}{dt}=4.47\ \text{km/h}$

The rate at which the distance between the ships is changing at 4 PM is $4.47\ \text{km/h}$ .

7 0

3 years ago