Pesticides and cancer drugs are both created by:

1. A 455 g mass, hanging at rest on a spring, stretches the spring 22.4 cm beyond its relaxed

pishuonlain [190]

Answer:

19.9 N/m

Explanation:

From the question,

Applying Hook's law

F = Ke.................. Equation 1

Where F = Force on the spring, k = spring constant, e = extension

But the force on the spring is the weight of the mass

Therefore,

mg = ke.................. Equation 2

Where m = mass. g = acceleration due to gravity

make e the subject of the equation

e = mg/e................ Equation 3

Given: m = 455 g = 0.455 kg, e = 22.4 cm = 0.224 m,

Constant: g = 9.8 m/s²

Substitute these values into equation 3

e = (0.455×9.8)/0.224

e = 19.9 N/m

6 0

3 years ago

When the system pressures are lower than the pressure in the refrigerant tank, such as when the system has just been evacuated o

steposvetlana [31]

Answer: True

Explanation:

It should be noted that when refrigerant is added in vapor form to the operating refrigeration system, then the addition of the refrigerant should be to the low-pressure side of the refrigeration system.

Furthermore, when system pressures are lower than the pressure in the refrigerant tank as stated in the question, then the refrigerant can be added to both the high and low pressure sides of the system.

Therefore, the correct option is true.

5 0

3 years ago

Digital thermometers often make use of thermistors, a type of resistor with resistance that varies with temperature more than st

Nezavi [6.7K]

Answer:

The temperature coefficient of resistivity for a linear thermistor is $1.38\times10^{-3}^{\circ}C^{-1}$

Explanation:

Given that,

Initial temperature = 0.00°C

Resistance = 75.0 Ω

Final temperature = 525°C

Resistance = 275 Ω

We need to calculate the temperature coefficient of resistivity for a linear thermistor

Using formula for a linear thermistor

$R=R_{0}(1+\alpha\Delta T)$

$R=R_{0}+R_{0}\alpha\Delta T$

$\alpha=\dfrac{R-R_{0}}{R_{0}\Delta T}$

Put the value into the formula

$\alpha=\dfrac{275-75}{275\times(525-0)}$

$\alpha=1.38\times10^{-3}^{\circ}C^{-1}$

Hence, The temperature coefficient of resistivity for a linear thermistor is $1.38\times10^{-3}^{\circ}C^{-1}$

4 0

3 years ago

Read 2 more answers

The________ channels sound to the eardrum.

inn [45]

The external auditory meatus, or ear canal, funnels sound to the eardrum. It is part of the outer ear.

6 0

3 years ago

PlS help <br>I really need help.<br>very urgent<br><br>PLS help

horsena [70]

Draw a freebody diagram, it will explain it really well

the boat is floating on top of the water, which means that the net acceleration in the y direction must be zero

the boat is not sinking (dominant downwards acceleration/force)
the boat is not flying (dominant upward acceleration/force)

that measn
$F_{net_y} =0$

now, if you drew the FBD, you only have 2 forces acting on the boat.
the upward bouyancy force on the boat and the downward force due to weight

$F_{net_y}= F_{bouyancy} - F_{weight}$

since the net force is equal to zero

$F_{bouyancy} - F_{weight} = 0$

and thus

$F_{bouyancy} = F_{weight}$

4 0

3 years ago