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4 years ago

Kelly sits on a rock. Her weight is an action force. What is the reaction force?

1 answer:

4 0

The force ffrom the ground that holds the rock up and prevents her from falling through the gound, unless the ground breaks.

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If it takes 560 joules of work to move an object 10 meters what force was needed

Pavel [41]

Answer:

F = 56 N

Explanation:

Assuming that the applied force is parallel to the displacement, according to the definition of work, we can write the following expression for the force required:

$F = \frac{W}{\Delta x} =\frac{560J}{10m} = 56 N (1)$

6 0

3 years ago

An 80kg parachutist jumps out of an airplane. Neglecting air friction, how fast will he be going after a 10 second free fall?

olganol [36]

If he is jumping you are adding force which means that you will be falling twice as fast

6 0

3 years ago

PLEASE HELP Which of the following describes the efficiency of real machines? 1.Efficiency is 100% 2.IMA is always larger than t

Rom4ik [11]

Answer:

IMA is always larger than the AMA

Explanation:

IMA is Ideal Mechanical Advantage and it equals the length of effort that is divided by the length of resistance which is given by the formula

IMA= Fr/Fe

Where Fr is the resistance force

Fe is the effort force.

IM= de/dr

Where de is the distance of the applied effort

dr is the distance traveled by the load.

In any real machine, the effort is needed to overcome friction and because of this, the ideal mechanical advantage(IMA) is always larger than the actual mechanical advantage (AMA)

5 0

3 years ago

Which of these results in kinetic energy of an object? a position b motion c mass d volume

Masja [62]

Answer:

Option B

Explanation:

Kinetic Energy is the energy possessed by the body due to <u>"motion"</u>.

3 0

3 years ago

Read 2 more answers

A ball is launched from ground level and hits the ground again after an elapsed time of 4 seconds and after traveling a horizont

Mumz [18]

Answer:

a. It is constant the whole time the ball is in free-fall

Explanation:

If we divide the movement on its vertical and horizontal components, and we concentrate on the vertical component, let's call x-component, and analyze Newton's second's law:

$\sum\overrightarrow{F_{x}}=m\overrightarrow{a_{x}}$

with $\sum\overrightarrow{F_{x}}$ , $a_{x}$ the acceleration on horizontal direction and m the mass of the ball, because the only force acting on the object is gravity that is always vertical, there're not forces on the horizontal direction that means $\sum\overrightarrow{F_{x}}=0$ and by (1) that implies $a_{x}$ =0 there's not acceleration on horizontal direction.

Because acceleration is the rate at what velocity changes and there's no acceleration, there's no change in velocity, in other words velocity is constant on horizontal direction.

6 0

3 years ago