A human eye is an example of a simple machine found in the human body. True or false

Calculate the acceleration if you push with a 20-N horizontal force against a 2-kg block on a horizontal friction- free air tabl

Nuetrik [128]

<span>10 meters per second. The formula is F = ma, so to solve we substitute 20 for F, 2 for m and then solve for a. 20 divided by 2 - 10, therefore the acceleration is 10 meters per second.</span>

8 0

3 years ago

Chris shoots an arrow up into the air. The height of the arrow is given by the function h(t) = - 16t2 + 32t + 26 where t is the

seropon [69]

Answer:

The maximum height of the arrow is 42 (and the units given for the height)

Explanation:

Everything is easier if you make a graph, you can give values to t and replace that values in the function, for example:

When t=0

$h(0)=-16(0^{2})+32(0)+26$

h(0)=26

If you give some values to t you can see how the trajectory of the arrow is (please look the graphic below)

Now, to find the maximum you have to find the derivative of the function that describes the height of the arrow:

$h(t)=-16t^{2}+32t+26$

$h'(t)=-32t+32$

Then you have to take the derivative, and equals to zero to find t:

-32t+32=0

-32t=32

t=1

That is in the time of 1 second the arrow has its maximum height.

Now you have to replace this value in the original function, to find the height of the arrow:

$h(1)=-16(1^{2})+32(1)+26$

h(1)=-16+32+36

h(1)=42

4 0

3 years ago

Two technicians are discussing a problem where the brake pedal travels too far before the vehicle starts to slow. Technician A s

iVinArrow [24]

Answer:

Technician A

Explanation:

If Technician B was correct, and the master cylinder is defective - then no braking action would occur.

This is not true however, as some breaking action eventually occurs, meaning it must be out of adjustment.

3 0

4 years ago

A lamp can work on 50V mains taking 2 amps. What value of resistance must be connected in series with it, so that it can be oper

wolverine [178]

The resistance of the lamp is apparently 50V/2A = 25 ohms.

When the circuit is fed with more than 50V, we want to add
another resistor in series with the 25-ohm lamp so that the
current through the combination will be 2A.

In order for 200V to cause 2A of current, the total resistance
must be 200V/2A = 100 ohms.

The lamp provides 25 ohms, so we want to add another 75 ohms
in series with the lamp. Then the total resistance of the circuit is
(75 + 25) = 100 ohms, and the current is 200V/100 ohms = 2 Amps.

The power delivered by the 200V mains is (200V) x (2A) = 400 watts.

The lamp dissipates ( I² · R ) = (2² · 25 ohms) = 100 watts.

The extra resistor dissipates ( I² · R) = (2² · 75 ohms) = 300 watts.

Together, they add up to the 400 watts delivered by the mains.

CAUTION:
300 watts is an awful lot of power for a resistor to dissipate !
Those little striped jobbies can't do it.
It has to be a special 'power resistor'.
300 watts is even an unusually big power resistor.
If this story actually happened, it would be cheaper, easier,
and safer to get three more of the same kind of lamp, and
connect THOSE in series for 100 ohms. Then at least the
power would all be going to provide some light, and not just
wasted to heat the room with a big moose resistor that's too
hot to touch.

3 0

3 years ago

The mass of the Sun is 1. 99 × 1030 kg. Jupiter is 7. 79 × 108 km away from the Sun and has a mass of 1. 90 × 1027 kg. The gravi

german

The gravitational force is s type of force that has the ability to attract any two objects having mass. The gravitational force will be $4.16\times10^{23}$ .

<h3>What is the gravitational force?</h3>

The gravitational force is s type of force that has the ability to attract any two objects with mass. Gravitational force tries to pull two masses towards each other.

$F= G\frac{m_1m_2}{r^{2} }$