Answer:
D?
Explanation:
Newton's Third Law of Motion: For every action, there is an opposite reaction, and forces come in pairs
<h2>Answer:</h2>
The option C is the correct answer.
Which is, "He varies the nitrogen and carbon dioxide levels in the air from one trial to the next".
<h3>Explanation:</h3>
The hypothesis of Malik was about the effect of increased oxygen level on the growth of the red-legged grasshoppers.
So the areas of his experiment should be the:
- Grasshopper type.
- High oxygen level.
- Rate of growth of grasshopper.
So all the given options are relevant to his experiment except the third one.
So varying the nitrogen and carbon dioxide level in air could not contribute in his experiment.
<h2 />
Answer:
Explanation:
Let m be mass of each sphere and θ be angle, string makes with vertex in equilibrium.
Let T be tension in the hanging string
T cosθ = mg ( for balancing in vertical direction )
for balancing in horizontal direction
Tsinθ = F ( F is force of repulsion between two charges sphere)
Dividing the two equations
Tanθ = F / mg
tan17 = F / (7.1 x 10⁻³ x 9.8)
F = 21.27 x 10⁻³ N
if q be charge on each sphere , force of repulsion between the two
F = k q x q / r² ( r is distance between two sphere , r = 2 x .7 x sin17 = .41 m )
21.27 x 10⁻³ = (9 X 10⁹ x q²) / .41²
q² = .3973 x 10⁻¹²
q = .63 x 10⁻⁶ C
no of electrons required = q / charge on a single electron
= .63 x 10⁻⁶ / 1.6 x 10⁻¹⁹
= .39375 x 10¹³
3.9375 x 10¹² .
The answer for this question, If I am correct, should be answer "D".
All wheelchairs may be secured
so that the user is facing the curb side of the vehicle is true. The answer is
letter A. It provides a unique 180 degree powered rotation which makes it
possible to raise, lower and rotate fully.
