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borishaifa [10]

3 years ago

7

a bike is moving with a velocity of 90km/hr.after applying break it stops in 5 sec. calculate the force applied by brakes .mass

of motercycle and rides is 200 kg

1 answer:

pentagon [3]3 years ago

7 0

Explanation:

initial velocity(u) = 90 km/s = 25 m/s

time (t) = 5 sec

mass (m) = 200 kg

final velocity (v) = 0 m/s

v = u + at

0 = 25 + a * 5

-25 = 5 a

-5 = a

Therefore acceleration = -5m/s²

Force = mass * acceleration

F = 200*-5

F = -1000 N

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Two workers pull horizontally on a heavy box. but one pulls twice as hard as the other. The larger pull is directed at 21.0° wes

pantera1 [17]

Answer:

The magnitude of F1 is

$|F1|=358.74 \ N$

The magnitude of F2 is

$|F2|=179.37\ N$

And the direction of F2 is

$\alpha = 44.214^o$

Explanation:

<u>Net Force </u>

Forces are represented as vectors since they have magnitude and direction. The diagram of forces is shown in the figure below.

The larger pull F1 is directed 21° west of north and is represented with the blue arrow. The other pull F2 is directed to an unspecified direction (red arrow). Since the resultant Ft (black arrow) is pointed North, the second force must be in the first quadrant. We must find out the magnitude and angle of this force.

Following the diagram, the sum of the vector components in the x-axis of F1 and F2 must be zero:

$\displaystyle -2F\ sin21^o+F\ cos\alpha =0$

The sum of the vertical components of F1 and F2 must equal the total force Ft

$\displaystyle -2F\ cos21^o+F\ sin\alpha =460$

Solving for $\alpha$ in the first equation

$\displaystyle cos\alpha =\frac{2F\ sin21^o}{F}=2sin21^o$

$\displaystyle cos\alpha =0.717=>\alpha =44.214^o$

$\displaystyle F(2cos21^o+sin\alpha)=460$

$\displaystyle F=\frac{460}{2cos21^o+sin\alpha}$

$\displaystyle F=\frac{460}{2cos21^o+sin44.214^o}$

$\displaystyle F=179.37\ N$

The magnitude of F1 is

$|F1|=2*F=358.74 \ N$

The magnitude of F2 is

$|F2|=179.37\ N$

And the direction of F2 is

$\alpha = 44.214^o$

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3 years ago

"The burning of fossil fuels produces gases which are capable of trapping heat resulting into the current rise in the global tem

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Answer:

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