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3 years ago

11

A driver in a car traveling at a speed of 26.8 m/s sees a deer 100 m away on the road. Calculate the minimum constant accelerati

on that is necessary of the car to stop without hitting the deer (assuming the deer does not move).
-4.20 m/s2

-1.75 m/s2

-2.89 m/s2

-3.59 m/s2

1 answer:

ZanzabumX [31]3 years ago

6 0

-3.5912m/s^2Use vf^2 = vi^2 + 2ax in your calculations, knowing vf, vi, and x.

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2 years ago

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If an object is to rest on an incline without slipping, then friction must equal the component of the weight of the object paral

leonid [27]

Answer:

$\theta = tan^{-1}\mu$

Explanation:

As we know that if the object is placed on the inclined plane then the force of friction on the object is counterbalanced by the component of the weight of the object along the inclined plane.

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$F_f = mgsin\theta$

now if we increase the inclination of the plane then the component of the weight weight along the inclined plane will increase and hence the friction force will also increase.

As we know that the limiting value or the maximum value of friction force at the static condition is given by

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so we have

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3 years ago

A lamp is 10% efficient.How much electrical energy must be supplied to the lamp each second if it produces 20 J of light energy

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If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.

20 J/s = 10% of Supply

20 J/s = (0.1) x (Supply)

Divide each side by 0.1:

Supply = (20 J/s) / (0.1)

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3 years ago

A rollercoaster car has 2500 J of potential energy and 160 J of

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Answer:

E_{k2}=2660 [J] kinetic energy.

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The energy in the initial state i.e. when the rollercoaster is at the top is equal to the energy in the final state i.e. when it is at the bottom of the hill.

These states can be represented by means of the second equation.

$E_{k1}+E_{p1}=E_{k2}\\160 + 2500 = E_{k2}\\E_{k2}=2660 [J]$

Since the rollercoaster is located in the bottom of the hill where the potential energy level is zero, therefore there is only kinetic energy in the second state.

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