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2 years ago

14

Melissa's favorite exercise equipment at the gym consists of various springs. in one exercise, she pulls a handle grip attached

to the free end of a spring to 0.80 m from its unstrained position. the other end of the spring (spring constant = 45 n/m) is held in place by the equipment frame. what is the magnitude of the force that melissa is applying to the handle grip?

1 answer:

konstantin123 [22]2 years ago

6 0

The formula for force exerted on/by a spring is

F = k*e where k is the spring constant and x is the distance stretched from unstrained position. This should allow you to find what you need.

Using F = k x e,

where k is the spring constant,

and e is the extension,

The F is her weight = 45 X 0.80

= 36 N

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Answer:

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As per the question:

Constant velocity of the horse in the horizontal, $v_{x} = 1 ft/s$

Distance of the horse on the horizontal axis, x = 10 ft

Vertical distance, y = 20 ft

Now,

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$l^{2}= 500$

Now,

$x^{2} + y^{2} = 500$ (1)

Differentiating equation (1) w.r.t 't':

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$x\frac{dx}{dt} = - y\frac{dy}{dt}$

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$\frac{dy}{dt}$ = Rate of change of displacement along the vertical

$v_{x}$ = velocity along the x-axis.

$v_{y}$ = velocity along the y-axis

$xv_{x} = -yv_{y}$

$v_{y} = - 10\times \frac{1}{20} = - 0.5 ft/s$

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Acceleration of the hay bale is given by the kinematic equation:

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Marta_Voda [28]

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a)

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C)

If the tree is very tall, the fall of the coconut lasts long, and the speed of the coconut keeps increasing. Since the air resistance is proportional to the speed, this means that at some point, the air resistance is no longer negligible, and it starts to have some effect on the fall of the coconut. In particular, at a certain point, the air resistance will become equal (in magnitude) to the force of gravity (but opposite in direction): this means that from this point, the acceleration of the coconut will be zero, and therefore the coconut will continue its motion at constant velocity. This velocity is called terminal velocity, and it occurs when the force of gravity is equal to the air resistance:

$mg = F_r$

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