Answer:
displacement at 45 s  =  30
                            65 s  = 50
So the average speed over the interval from 45 s to 65 s is
(50 - 30) cm / 20 s = 1 cm / sec
As a check an average speed of 1 cm / sec for 20 sec will produce a
displacement of 1 cm / sec * 20 sec = 20 cm  or from 30 to 50 cm
 
        
             
        
        
        
Answer:
23.889 Celcius
Explanation:
(75°F − 32) × 5/9 = 23.889°C
 
        
                    
             
        
        
        
        
Answer:
resistance of a conductor increases 
Explanation:
The resistance of conductors is directly proportional to the temperature of the conductor. This implies that when the temperature of the conductor is increased, the resistance of the conductor increases likewise.
This is applied in the resistance thermometer. Resistance thermometers are useful for accurate temperature measurements at very high or very low temperatures.