In Fraunhofer diffraction wave front used is __________. A. Spherical B. Circular C. Plane D. Conical

Megan wants to see if mice that are fed food A or B grow at a faster rate. She measures the mass of the mice on day 1, then divi

diamong [38]

<span>No, there is no control group because each group is treated under test conditions.</span>

7 0

3 years ago

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An electric device, which heats water by immersing a resistance wire in the water, generates 50 cal of heat per second when an e

Oksi-84 [34.3K]

Answer:

0.69 ohm

Explanation:

Heat generated per second, H = 50 cal/s

Potential difference, V = 12 V

Let R is the resistance of coil.

The formula for the heat is given by

$H = \frac{V^{2}}{R}t$

$50\times 4.186 = \frac{12^{2}}{R}\times 1$

R = 0.69 ohm

3 0

3 years ago

Which is a characteristic that makes electromagnetic waves and water waves different

Paraphin [41]

We know that a wave is a disturbance that transfers energy through matter or space There are two main types of waves: Mechanical and Electromagnetic. Water waves are mechanical. A mechanical wave is an oscillation of matter to transfers energy, but you always need a medium (substance such as: solid, liquid, gas, plasma) to transport it. The medium for water waves is, in fact, the water. For example, ripple in water is a surface wave. On the other hand, electromagnetic waves don't need a medium to transport, they can do it through the empty space. Then, this is the major characteristic that makes these two types of waves different.

4 0

3 years ago

Q. A mass of 300g is lifted to a<br> height of 10m<br> 205 by a person. Calculate his work done

sergiy2304 [10]

A=mgh
m=300g=0.3kg
g=9,81 m/s^2
h=10m
A=29.43J

3 0

2 years ago

You know your mass is 62 kg but when you stand on a bathroom scale in an elevator it says your mass is 77 kg what is the acceler

lbvjy [14]

In a stationary situation, the weight of person is
$W=mg=(62 kg)(9.81 m/s^2) = 608.2 N$
This is the weight "felt" by the scale, which is basically the normal reaction applied by the scale on the person, and which uses the value of g (9.81) as reference to convert the weight (602.8 N) into a mass (62 kg).

When the person is in the elevator, the scale says 77 kg. The scale is still using the same value of conversion (9.81), so the apparent weight "felt" by the scale is
$W' = m'g=(77 kg)(9.81 m/s^2)=755.4 N$
This is the normal reaction applied by the scale on the person, and which is directed upward. Besides this force, there is still the weight W of the person, acting downward. So, if we use Newton's second law:
$\sum F = ma$
$W-W'=ma$
where a is the acceleration of the elevator. If we solve for a, we find
$a= \frac{W-W'}{m}= \frac{608.2N-755.4N}{62 kg}=-2.37 m/s^2$
The negative sign means the acceleration is in the opposite direction of g (which we take positive), so it means the elevator is going upward.

4 0

3 years ago