<span>The answer is C. temperature, light level, species of bacteria. All three variables are considerations regarding the reproduction rate of the bacteria. The other three answer choices can be eliminated easily because they each contain at least one irrelevant variable. In particular, all three contain a variable that makes reference to Jack's personal characteristics. These do not have any impact on the experiment and readily stand out to disqualify the entire answer choice.</span>
Answer:
1.69 T
Explanation:
Applying,
F = BvqsinФ.................. Equation 1
Where F = Force, B = magnetic field, v = velocity, q = charge on an electron, Ф = angle between the electron and the field.
make B the subject of the equation,
B = F/(vqsinФ)............. Equation 2
From the question,
Given: F = 2.0×10⁻¹³ N, v = 7.4×10⁵ m/s, Ф = 90°
Constant: q = 1.60×10⁻¹⁹ C
Substitute into equation 2
B = 2.0×10⁻¹³/(7.4×10⁵×1.60×10⁻¹⁹×sin90°)
B = 0.169×10
B = 1.69 T
Answer:
20.179 x 10⁶ J /kg
Explanation:
The food after the reaction gives out heat which increases the temperature of water and air in the reaction chamber . The heat absorbed by water and air gives the estimate of energy content of the food.
Heat absorbed by water = mass x specific heat x rise in temperature
= 3 x 4.18 x 10³ x 3.2
= 40.128 x 10³ J
Heat absorbed by air = mass x specific heat x rise in temperature
0.1 x 3. 2 x .718 x 10³
= 0.23 x 10³
Total heat energy evolved
= 40.358 x 10³ J
This energy is evolved by 2 x 10⁻³ kg of food
energy content per kg of food
= 40.358 x 10³ / 2 x 10⁻³
= 20.179 x 10⁶ J /kg
