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andrey2020 [161]

2 years ago

12

3. What is the distance between New York and London, if an airplane flying at 580 Km per hour takes 7 hours to complete the trip

?

1 answer:

Naddik [55]2 years ago

4 0

Answer:

4060 km

Explanation:

580 km/hr * 7 hr = 4060 km

rate * time = distance

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A car slows down at -5.00 m/s² until it comes to a stop after travelling 15.0 m. What was the initial speed of the car?

lapo4ka [179]

<h2>Answer: 12.24m/s</h2>

According to <u>kinematics</u> this situation is described as a uniformly accelerated rectilinear motion. This means the acceleration while the car is in motion is constant.

Now, among the equations related to this type of motion we have the following that relates the velocity with the acceleration and the distance traveled:

$V_{f}^{2}-V_{o}^{2}=2.a.d$ (1)

Where:

$V_{f}$ is the Final Velocity of the car. We are told "the car comes to a stop after travelling", this means it is 0.

$V_{o}$ is the Initial Velocity, the value we want to find

$a$ is the constant acceleration of the car (the negative sign means the car is decelerating)

$d$ is the distance traveled by the car

Now, let's substitute the known values in equation (1) and find $V_{o}$ :

$0-V_{o}^{2}=2(-5m/{s}^{2})(15m)$ (2)

$-V_{o}^{2}=-150{m}^{2}/{s}^{2}$ (3)

Multiplying by -1 on both sides of the equation:

$V_{o}^{2}=150{m}^{2}/{s}^{2}$ (4)

$V_{o}=\sqrt{150{m}^{2}/{s}^{2}}$ (5)

Finally:

$V_{o}=12.24m/s$ >>>This is the Initial velocity of the car

5 0

2 years ago

A 60-m-long chain hangs vertically from a cylinder attached to a winch. Assume there is no friction in the system and that the

Mariulka [41]

Answer:

part (a). 176580 J

part (b). 197381 J

Explanation:

Given,

Density of the chain = $\rho\ =\ 10\ kg/m.$
Length of the chain = L = 60 m
Acceleration due to gravity = g = 9.81 $m/s^2$

part (a)

Let dy be the small element of the chain at a distance of 'y' from the ground.

mass of the small element of the chain = $\rho dy$

Work done due to the small element,

$dw\ =\ \rho g (60\ -\ y)dy\\$

Total work done to wind the entire chain = w

$w\ =\ \displaystyle\int_{0}^{L} \rho g(60\ -\ y)dy\\\Rightarrow w\ =\ \rho g\left |(60y\ -\ \dfrac{y^2}{2})\ \right |_{0}^{60}\\\Rightarrow w\ =\ 10\times 9.81\times (60\times 60\ -\ \dfrac{60^2}{2})\\\Rightarrow w\ =\ 176580\ J$

part (b)

mass of the block connected to the chain = m = 35 kg

Total work done to wind the chain = work done due to the chain + work done due to the mass

$\therefore W\ =\ w\ +\ mgL\\\Rightarrow W\ =\ 176580\ +\ 35\times 9.81\times 60\\\Rightarrow W\ =\ 176580\ +\ 20601\\\Rightarrow W\ =\ 197381\ J$

4 0

2 years ago

Identify some sports or activities you can do to improve your overall health and explain how physical activity can improve your

Alexxx [7]

Answer:

soccer

Explanation:

soccer can inprove your health because you use all parts of your body playing it. You use your legs because you are running and you use your arms for doing throw ins. Soccer is also good for you because you are not playing for too long. Usually one soccer game is only 1 hour.

Hope this helps

3 0

2 years ago

A juggler throws a bowling pin straight up with an initial speed of 8.20 m/s. How much time elapses until the bowling pin return

tensa zangetsu [6.8K]

Answer:

1.68 s

Explanation:

From newton's equation of motion,

a = (v-u)/t.................................. Equation 1

Making t the subject of the equation

t =(v-u)g............................. Equation 2

Where t = time taken for the bowling pin to reach the maximum height, v = final velocity bowling pin, u = initial velocity of the bowling pin, g = acceleration due to gravity.

Note: Taking upward to be negative and down ward to be positive,

Given: v = 0 m/s ( at the maximum height), u = 8.20 m/s, g = -9.8 m/s²

t = (0-8.20)/-9.8

t = -8.20/-9.8

t = 0.84 s.

But,

T = 2t

Where T = time taken for the bowling pin to return to the juggler's hand.

T = 2(0.84)

T = 1.68 s.

T = 1.68 s

7 0

2 years ago

Looking that following diagram of bar magnets, determine if the magnets will or will not connect (attract) and why.

vovangra [49]

Answer: They will NOT connect because like poles are facing each other, and like poles repel each other.

3 0

3 years ago