Answer:
t = 6.09 seconds
Explanation:
Given that,
Speed, v = 44.1 cm/s
Distance, d = 269 cm 
We need to find the time interval of the marble. Speed is distance per unit time.

Hence, the time interval of the marble is 6.09 seconds.
 
        
             
        
        
        
Answer:
Scientific knowledge is used to create new technologies. New technologies often allow scientists to explore nature in different ways and make new discoveries. 
Explanation:
 
        
                    
             
        
        
        
Answer:
1/3 the distance from the fulcrum
Explanation:
On a balanced seesaw, the torques around the fulcrum calculated on one side and on another side must be equal. This means that:

where
W1 is the weight of the boy
d1 is its distance from the fulcrum
W2 is the weight of his partner
d2 is the distance of the partner from the fulcrum
In this problem, we know that the boy is three times as heavy as his partner, so 

If we substitute this into the equation, we find:

and by simplifying:

which means that the boy sits at 1/3 the distance from the fulcrum.
 
        
             
        
        
        
Answer:
9ms^2
Explanation:
since ,Force=mass*acceleration
then, acceleration=force/mass
and, Force=90N
 Mass=10pound
therefore, acceleration=90/10
 =9ms^2
 
        
             
        
        
        
Answer:
<h3>e)</h3><h3>
<u>Question</u><u>:</u><u>-</u></h3>
- Electroplating is based on magnetic effect of electricity.
<h3>
<u>Answer</u><u>:</u><u>-</u></h3>
- <em>It's</em><em> </em><em>incorrect</em><em> </em><em>sentence</em><em> </em>
- As we know that, while electroplating there are two rods, one becoming cathode and another one becoming anode. During electroplating, when electricity is given through the rods, the anode produces positive ions which gets received at the cathode rod and negative ions produced at cathode collects at anode rod which results to the plating of the desired substance. Here, it is a chemical effect of electricity resulting to plating.
<u>So correct sentence is:</u>
- <em>Electroplating</em><em> </em><em>is</em><em> </em><em>based</em><em> </em><em>of</em><em> </em><em>chemical</em><em> </em><em>effect</em><em> </em><em>of</em><em> </em><em>electricity</em><em>.</em><em> </em>
<h3>f)</h3><h3>
<u>Question</u><u>:</u><u>-</u></h3>
- An electric bulb glows due to the chemical effect of electricity.
<h3>
<u>Answer</u><u>:</u><u>-</u></h3>
- <em>It's</em><em> </em><em>incorrect</em><em> </em><em>sentence</em><em> </em>
- As we know that, in an electric bulb there is a filament. When electricity is given in that filament of the electric bulb, the filament gets intensely heated up and results to the emission of light. Due to this heating of the filament due to electricity the electric bulb glows.
<u>So correct sentence is:</u>
- <em>A</em><em>n electric bulb glows due to the </em><em>h</em><em>e</em><em>a</em><em>t</em><em>i</em><em>n</em><em>g</em><em> </em><em>effect of electricity.</em>