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3 years ago

An object moving with a speed of 21 m/s and has a kinetic energy of 140 J, what is the mass of the object.

Physics

2 answers:

alexira [117]3 years ago

7 0

Answer:2940

Explanation:

Masteriza [31]3 years ago

7 0

Answer:

0.635 kg

Explanation:

Recall that Kinetic energy is defined as:

K.E. = (1/2) mv²,

where

K.E = Kinetic energy = given as 140J

m = mass (we are asked to find this)

v = velocity = given as 21 m/s

Substituting the above values into the equation:

K.E. = (1/2) mv²

140 = (1/2) m (21)² (rearranging)

m = (140)(2) / (21)²

m = 0.635 kg

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snow_tiger [21]

Answer:0.69

Explanation:

Coefficient of kinetic friction=f/R=61.8/90=0.69

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3 years ago

PLEASE HELP ME (stop putting links ) Two objects m1 and m2, each with a mass of 5 kg and 6 kg separated by a distance. A third o

BabaBlast [244]

Answer:

Explanation:

Newton's Gravitation Law

$\displaystyle \frac{GmM}{d^2}$

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3 years ago

The plane of a rectangular coil, 7.2 cm by 3.7 cm, is perpendicular to the direction of a uniform magnetic field B. If the coil

netineya [11]

Answer:

The rate of change of magnetic field is 2.23 T/s.

Explanation:

Given that,

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Number of turns in the coil, N = 104

Resistance of the coil, R = 12.4 ohms

Current, I = 0.05 A

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$\epsilon=-\dfrac{d\phi}{dt}$

Ohm's law is :

$\epsilon=IR$

So,

$IR=-\dfrac{d\phi}{dt}\\\\IR=-\dfrac{d(NBA)}{dt}\\\\IR=-NA\dfrac{dB}{dt}\\\\\dfrac{dB}{dt}=\dfrac{IR}{NA}\\\\\dfrac{dB}{dt}=\dfrac{0.05\times 12.4}{104\times 7.2\times 10^{-2}\times 3.7\times 10^{-2}}\\\\\dfrac{dB}{dt}=2.23\ T/s$

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3 years ago

Block B has mass 6.00 kg and sits at rest on a horizontal, frictionless surface. Block A has mass 2.50 kg and sits at rest on to

zzz [600]

Answer:

Explanation:

Block A sits on block B and force is applied on block A . Block A will experience two forces 1) force P and 2 ) friction force in opposite direction of motion . Block B will experience one force that is force of friction in the direction of motion .

Let force on block A be P . friction force on it will be equal to kinetic friction, that is μ mg , where μ is coefficient of friction and m is mass of block A

friction force = .4 x 2.5 x 9.8

= 9.8 N

net force on block A = P - 9.8

acceleration = ( P - 9.8 ) / 2.5

force on block B = 9.8

acceleration = force / mass

= 9.8 / 6

for common acceleration

( P - 9.8 ) / 2.5 = 9.8 / 6

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P = 13.88 N .

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4 years ago

Calcular la rapidez promedio

Vlada [557]

Answer:

v_average = 15 m / s

Explanation:

The average speed can be found in two ways,

* taking the distance traveled and divide it by the time spent

* taking the velocities in each time interval and then finding the weighted average by the time fraction

v_average = 1 / t_total ∑ $v_{i} t_{i}$ vi ti

Let's apply this last equation

Total time is

t = t₁ + t₂

t = 10 + 10 = 20 min

v_average = 10/20 10 + 10/20 20

v_average = 10/2 + 20/2

v_average = 15 m / s

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3 years ago