Answer:
A. Power = Work / Time
Explanation:
Power is the amount of work done over time, or rather the rate of work, which is given by the unit of watts (W). Since work is defined by Force * Displacement, we can also say Power = Force * Displacement / Time.
Answer:
The centripetal force will be 1/2 as big as it was. (option c)
Explanation:
Recall that centripetal force (
) is defined as: 
where "v" is the tangential velocity of the object in circular motion, "r" is the radius of rotation and "m" is the object's mass.
So if we start with such formula with a given mass, radius, and tangential velocity, and then we move to a situation where everything stays the same except for the radius which doubles, then the new centripetal force (
) will be given by: 
and this is half (1/2) of the original force:
which is expressed by option "c" of the provided list.
Answer:
a = 5 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity = 20 [m/s]
Vo = initial velocity = 10 [m/s]
t = time = 2 [s]
a = acceleration [m/s²]
Now replacing:
![20 =10 +a*2\\10=2*a\\a=5[m/s^{2} ]](https://tex.z-dn.net/?f=20%20%3D10%20%2Ba%2A2%5C%5C10%3D2%2Aa%5C%5Ca%3D5%5Bm%2Fs%5E%7B2%7D%20%5D)
You probably do this as a DC circuit which is not quite correct, but it will get you an answer. The study is a great deal more complicated.
Problem One: Secondary Power.
W = E * I
E = 10 A
I = 24V
W = 24 * 10
W = 240 Watts.
Here's the thing you have to know. These transformers are 100% efficient (or are assumed so). So whatever wattage is in the secondary, it is the same as that in the primary.
Primary Power = Secondary Power
Secondary Power = 240 Watts
Primary Power = 240 Watts
W = E * I
E = 240 volts
W = 240 watts
I = W/E = 240 / 240
I = 1 Amp. Answer Part One
Part Two
Answered above. 240 watts.
Part Three
Answered above. 240 watts.
Secondar
