Answer:
(a) The ratio of turns in the primary and secondary coils of her transformer is 1.833
(b) The ratio of input to output current is 0.55
(c) To increase the output voltage, you can either increase the number of turns in the secondary coil (step-up) or increase the input current. Therefore, the Chinese person has to increase the input current of the transformer to achieve an increased output voltage that can power her 220 V appliances.
Explanation:
Given;
input voltage, = 220 V
output voltage, = 120 V
General transformer equation is given as;
where;
Np is number of turns in the primary coil
Ns is number of turns in the secondary coil
Is - is the secondary current or output current
Ip - is the primary current or input current
(a) The ratio of turns in the primary and secondary coils of her transformer;
(b) The ratio of input to output current;
(c) To increase the output voltage, you can either increase the number of turns in the secondary coil (step-up) or increase the input current. Therefore, the Chinese person has to increase the input current of the transformer to achieve an increased output voltage that can power her 220 V appliances.
Answer: 3.5 seconds
EXPLANATION:
Using the formula:
v = u + at
And taking the upwards direction as positive, we have the following information:
u = 35 m/s
a = -10m/s^2 (this is acceleration due to gravity)
At the top of its path, the apple will have a velocity of 0 m/s, therefore:
v = 0m/s
Once you substitute everything into the formula, you get:
0 = 35 + (-10)t
Therefore, t = 35/10 = 3.5 seconds
Since we know that
Gravitational potential energy = mass × height ×gravity
then
GPE = 1.5 kg x 0.500 m x 9.8m/s^2
therefore
GPE = 7.35 J
Answer:
Basic kinematics, negating drag and assuming ideal conditions, we use the equation:
d=vi*t+1/2*a*t^2
Since vi is 0 (we know this because you’re dropping it, not throwing it)…
…and the only acceleration acting on it is gravity, a=9.8 m/s^2…
…we get
d=1/2(9.8)(5)^2
Explanation:
Some quick mental math tells us that this is about 125 m.
Plugging it in, we find it to be 122.5 m.