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3 years ago

Kindly explain question numbers 26 and 27

Physics

1 answer:

stich3 [128]3 years ago

7 0

26).

The complete pattern of a pendulum is ...

-- out to one side

-- back to the center

-- out to the OTHER side

-- back to the center.

So, on the graph, the complete period is one up-loop and one down-loop.

That's <em>6 seconds</em>. (b)

27).

This question is just asking for the frequency, without using the word.

Frequency is always (1/period). That's <em>1/6 of a second</em>. (a)

(This kinda makes sense. If you want to do something in 6 seconds, you need to do 1/6 of it every second. Right ?)

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What is 95°F on the Celsius scale?

svetlana [45]

95 degrees Fahrenheit in Celsius scale is 35 degrees Celsius

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3 years ago

A 25.0 kg block is initially at rest on a horizontal surface. A horizontal force of 75.0 N is required to set the block in motio

QveST [7]

Answer:

(a) 0.31

(b) 0.245

Explanation:

(a)

F' = μ'mg.................... Equation 1

Where F' = Horizontal Force required to set the block in motion, μ' = coefficient of static friction, m = mass of the block, g = acceleration due to gravity.

make μ' the subject of the equation above

μ' = F'/mg............. Equation 2

Given: F' = 75 N, m = 25 kg

constant: g = 9.8 m/s²

Substitute these values into equation 2

μ' = 75/(25×9.8)

μ' = 75/245

μ' = 0.31.

(b) Similarly,

F = μmg.................. Equation 3

Where F = Horizontal force that is required to keep the block moving with constant speed, μ = coefficient of kinetic friction.

make μ the subject of the equation

μ = F/mg.............. Equation 4

Given: F = 60 N, m = 25 kg, g = 9.8 m/s²

Substitute these values into equation 4

μ = 60/(25×9.8)

μ = 60/245

μ = 0.245

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3 years ago

A car travels 10.0 m/s. What is its velocity in km/h?

Vitek1552 [10]

Since 1m/s=3.6 km/h, we can conclude that 10.0m/s = 36 km/h

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3 years ago

Until a train is a safe distance from the station it must travel at 5 m/s. Once the train is on open track it can speed up to

Evgesh-ka [11]

Answer: 45x8=360 :)

Explanation:

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3 years ago

A 5.00 kg pendulum swings back and forth. At the top of its arc, it reaches a height of 0.36 m. What is the velocity of the pend

ella [17]

Tools we'll use:

--    Gravitational potential energy = (mass) x (gravity) x (height)

--    Kinetic energy (of a moving object) = (1/2) (mass) x (speed)²

When the pendulum is at the top of its swing,
its potential energy is

   (mass) x (gravity) x (height)

   = (5 kg) x (9.8 m/s²) x (0.36 m)

   = (5 x 9.8 x 0.36) joules

   = 17.64 joules .

Energy is conserved ... it doesn't appear or disappear ...
so that number is exactly the kinetic energy the pendulum
has at the bottom of the swing, only now, it's kinetic energy:

   17.64 joules = (1/2) x (mass) x (speed)²

   17.64 joules = (1/2) x (5 kg) x (speed)²

Divide each side by 2.5 kg:

   17.64 joules / 2.5 kg = speed²

Write out the units of joules:

   17.64 kg-m²/s² / 2.5 kg = speed²

   (17.64 / 2.5) (m²/s²) = speed²

   7.056 m²/s² = speed²

Take the square root
of each side: Speed = √(7.056 m²/s²)

   = 2.656 m/s .

Looking through the choices, we're overjoyed to see
that one if them is ' 2.7 m/s '. Surely that's IT !
_______________________________

Note:
The question asked for the pendulum's 'velocity', but our (my) calculation
only yielded the speed.

In order to describe a velocity, the direction of the motion must be known,
and the question doesn't give any information on exactly how the pendulum
is hanging, and how it's swinging.

We know that at the bottom of its swing, the motion is completely horizontal,
but we have no clue as to what direction. So all we can discuss is its speed.

6 0

3 years ago