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2 years ago

10

What horizontal velocity should be given to a ball hanging on a 4.9 m long thread so that it slides to the height of the hanger

(do not take into account the force of air resistance)

1 answer:

igomit [66]2 years ago

5 0

Answer:

13 u2 = 0 – (2 × –2 m/s2 × 6 m) = 24, u = 4.9 m

Explanation:

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A curve in a stretch of highway has radius R. The road is not banked in any way. The coefficient of static friction between the

adelina 88 [10]

Answer:

maximum possible velocity = $\sqrt{ugR}$

Explanation:

centripetal acceleration when the car is going in the circle must be less than the maximum friction for the car to not slip.

centripetal acceleration $\frac{mv^{2}}{r}$

where v is the velocity of car and r is the radius of circle

maximum friction = umg

where u is the coefficient of static friction.

therefore $umg\geq \frac{mv^{2}}{R}$

therefore maximum possible velocity = $\sqrt{ugR}$

6 0

3 years ago

You yell into a canyon. You hear the echo in 3 seconds. How long did the sound of your voice travel before bouncing off a cliff?

Lilit [14]

Answer:

The sound travelled 516 meters before bouncing off a cliff.

Explanation:

The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:

$2\cdot h = v\cdot t$ (1)

Where:

$h$ - Height, measured in meters.

$v$ - Velocity of sound, measured in meters per second.

$t$ - Time, measured in seconds.

If we know that $v = 344\,\frac{m}{s}$ and $t = 3\,s$ , then the height of the canyon is:

$h = \frac{v\cdot t}{2}$

$h = \frac{\left(344\,\frac{m}{s} \right)\cdot (3\,s)}{2}$

$h = 516\,m$

The sound travelled 516 meters before bouncing off a cliff.

7 0

2 years ago

The pitch of a sound wave is its _________. <br> A.speed B.amplitude C.frequency D.wavelength

Artyom0805 [142]

Hi there my friend :)

Your answer is C. frequency

Hope this helps :)

-xxAnsxx-

8 0

3 years ago

An object of 4 kg has a speed of 6 m/s and moves a distance of 8 m. What is its kinetic energy in joules.

11Alexandr11 [23.1K]

Answer:

The answer to your question is Ke = 72 J

Explanation:

Kinetic energy depends on the speed of and object and its mass.

Data

mass = m = 4 kg

speed = v = 6 m/s

distance = d = 8 m

Kinetic energy = ke = ?

Formula

Ke = (1/2) mv²

Substitution

Ke = (1/2) (4)(6)²

Simplification

Ke = (1/2)(4)(36)

Ke = (1/2)(144)

Ke = 72 Joules

Result

Ke = 72 J

3 0

2 years ago

A student performs this experiment and measures the bar to have a mass of 150g and length of 36cm. What is the moment of inertia

Ugo [173]

Answer:

The moment of inertia of the bar is $45\times10^{-4}\ kg-m^2$

Explanation:

Given that,

mass of bar = 150 g

Length l = 36 cm

We need to calculate the moment of inertia of the bar

Using formula of moment inertia

$I=\dfrac{1}{12}Ml^2$

Where,

M = mass of the bar

L = length of the bar

Put the value into the formula

$I=\dfrac{1}{12}\times150\times10^-3\times36\times10^{-2}$

$I=45\times10^{-4}\ kg-m^2$

Hence, The moment of inertia of the bar is $45\times10^{-4}\ kg-m^2$

4 0

3 years ago