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3 years ago

Calculate the kinetic energy of a car of mass 800kg moving at 100 kmph.

Physics

1 answer:

valentina_108 [34]3 years ago

4 0

Answer:

KE = 308642.02469136 J

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Transverse waves are sent along a 4.50 m long string with a speed of 85.00 m/s. The string is under a tension of 20.00 N. What i

frutty [35]

Answer:

m = 0.0125 kg

Explanation:

Let us apply the formula for the speed of a wave on a string that is under tension:

$v = \sqrt{\frac{F}{\mu} }$

where F = tension force

μ = mass per unit length

Mass per unit length is given as:

μ = m / l

where m = mass of the string

l = length of the string

This implies that:

$v = \sqrt{\frac{F}{m/l} }\\ \\v = \sqrt{\frac{F * l}{m} }$

Let us make mass, m, the subject of the formula:

$v^2 = \frac{F * l}{m}\\\\m = \frac{F * l}{v^2}$

From the question:

F = 20 N

l = 4.50 m

v = 85 m/s

Therefore:

$m = \frac{20 * 4.5}{85^2}\\\\m = \frac{90}{7225}\\ \\m = 0.0125 kg$

5 0

3 years ago

A big lump of meat of mass 5Kg is hung from a spring balance in an elevator. Find the reading of the balance of (I) the elevator

Mrrafil [7]

The reading of the balance if ,

I ) If the elevator is moving with a steady speed = 50 N

II ) If the elevator is moving upwards with acceleration of 0.2 m / s² = 51 N

T = m g + m a

T = Force

m = Mass

g = Acceleration due to gravity

a = Acceleration

m = 5 kg

g = 10 m / s²

I ) If the elevator is moving with a steady speed,

At steady speed, a = 0

T = ( 5 * 10 ) + ( 5 * 0 )

T = 50 N

II ) If the elevator is moving upwards with acceleration of 0.2 m / s²,

a = 0.2 m / s²

T = ( 5 * 10 ) + ( 5 * 0.2 )

T = 50 + 1

T = 51 N

Therefore, the reading of the balance if ,

I ) If the elevator is moving with a steady speed = 50 N

II ) If the elevator is moving upwards with acceleration of 0.2 m / s² = 51 N

To know more about reading on a spring balance

brainly.com/question/14819147

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7 0

1 year ago

A tennis ball of mass 0.060 kg travels horizontally at a speed of 25m/s. The ball hits a tennis

stepladder [879]

It would be A because a is perfect

7 0

3 years ago

Read 2 more answers

The activity of a radioisotope is found to decrease 40% of its original value in 2.59 x 10 s.

Rainbow [258]

Answer: $0.0353\ s^{-1}$

Explanation:

Given

Radioactive material is found to decrease 40% of its original value in $2.59\times 10\ s$

Sample at any time is given by

$N=N_oe^{-\lambda t}$

where, $\lambda=\text{decay constant}$

Put values

$\Rightarrow 0.4N_o=N_oe^{-\lambda\cdot 2.59\times 10}\\\Rightarrow 0.4=e^{-\lambda\cdot 2.59\times 10$

Taking natural logarithm both side

$\Rightarrow \lambda=\dfrac{\ln 2.5}{25.9}\\\\\Rightarrow \lambda =0.0353\ s^{-1}$

8 0

3 years ago

A current of 12 A flows for 20 minutes into an electric cooker. How much charge has the cooker used?

cluponka [151]

Time= 20 minutes= 20*60=1200 s
Charge=current*time=12*1200=14400 C

7 0

3 years ago