To do that, you must pass electric current through a substance
that electrons have to spend energy to pass through.  
The substance will be one that gets warm and dissipates heat
when electric current flows through it.
 We'll say that the substance has "resistance", which we can measure.
The amount of heat that appears when current flows through it
will be (current²)·(resistance).
A few examples of things used for that purpose:
-- resistors
-- burners on electric stoves
-- coils of resistor-wire in a toaster
-- aquarium heater
-- electric clothes iron
-- electric coffee pot
-- blow-dryer
-- electric hair-curling iron
-- skinny tungsten wire in a light-bulb .
        
             
        
        
        
When the temperature increases, the intermolecular forces between the molecules of a liquid become weaker, and some bonds break easily. Thus as temperature increases, the surface tension of a liquid decreases.
        
             
        
        
        
Answer:
Delta_temp = 18[°F]
Explanation:
°F = 9/5*(10)
°F = 18
Note: It is important to clarify that it is only a temperature increase, that it is only a temperature increase. The question is not related to converting from 10°C to fahrenheit degrees
 
        
             
        
        
        
Answer:
the formula is efficiency = output / input × 100%
 
        
             
        
        
        
Answer:
4500 N
Explanation:
When a body is moving in a circular motion it will feel an acceleration directed towards the center of the circle, this acceleration is:
a = v^2/r
where v is the velocity of the body and r is the radius of the circumference:
Therefore, a body with mass m, will feel a force f:
f = m v^2/r
Therefore we need another force to keep the body(car) from sliding, this will be given by friction, remember that friction force is given a the normal times a constant of friction mu, that is:
fs = μN = μmg
The car will not slide if     f = fs,   i.e.
fs = μmg =  m v^2/r
That is, the magnitude of the friction force must be (at least) equal to the force due to the centripetal acceleration
fs = (1000 kg)  * (30m/s)^2 / (200 m) = 4500 N