Answer:
changing the polarity or direction of the battery changes the sign of the voltage and the current
Explanation:
The sign of current and voltage are due to established conventions.
The way that a DC circuit with negative current values is by changing the polarity of the power source or by inverting the battery, this creates that the electrons move in the opposite direction
Changing the battery also changes the direction of the power difference, since the potential from positive to negative, in most cases negative is assigned a potential of zero volts
In summary, changing the polarity or direction of the battery changes the sign of the voltage and the current
V = 340 m/s
f = 256 Hz
lambda (wavelength)
v = f*lambda
340 = 256 * lambda
340/256 = lambda
lambda = 1.328 m
Answer: Energy requirement or consumption also increases as frequency goes higher. Hence, those low-frequency to mid-frequency waves are commonly referred to as radio waves and essentially, they have longer wavelengths. On the other hand, microwaves have higher frequencies and shorter wavelengths.
Explanation: therefore that's why they don't travel faster.
Answer: a) 42Nm b) 8.4m/s
Explanation:
Impulse is defined as object change in momentum.
Since Force = mass × acceleration
F = ma
Acceleration is the rate of change in velocity.
F = m(v-u)/t
Cross multiply
Ft = m(v-u)
Since impulse = Ft
and Ft = m(v-u)... (1)
The object change in velocity (v-u) = Ft/m from eqn 1
Going to the question;
a) Impulse = Force (F) × time(t)
Given force = 14N and time = 3seconds
Impulse = 14×3
Impulse = 42Nm
b) The object change in velocity (v-u) = Ft/m where mass = 5kg
v-u = 14×3/5
Change in velocity = 42/5 = 8.4m/s
Answer:
velocity = distance / time taken
= 200/4
= 50 m/s
is the correct answer
