Answer:
The potential difference between the ends of a wire is 60 volts.
Explanation:
It is given that,
Resistance, R = 5 ohms
Charge, q = 720 C
Time, t = 1 min = 60 s
We know that the charge flowing per unit charge is called current in the circuit. It is given by :
I = 12 A
Let V is the potential difference between the ends of a wire. It can be calculated using Ohm's law as :
V = IR
V = 60 Volts
So, the potential difference between the ends of a wire is 60 volts. Hence, this is the required solution.
The acceleration of gravity is 9.8 m/s². That means that when something
is falling here on Earth, its speed increases by 9.8 m/s every second that
it falls. In other words, whenever you look at it, it's falling 9.8 m/s faster
than it was falling one second earlier.
If you drop an object from some high place ... high enough that it can
keep falling for 6 seconds and not hit the ground yet ... it falls 9.8 m/s
faster every second, and at the end of 6 seconds, it's falling at
(6) x (9/8 m/s) = 58.8 meters per second.
At the beginning of the 6 seconds, its speed was zero.
At the end of the 6 seconds, its speed is 58.8 meters per second.
Its AVERAGE speed over the period of 6 seconds is
(1/2) (0 + 58.8 m/s)
= 29.4 meters per second .
Distance = (average speed) x (time)
= (29.4 m/s) x (6 sec)
= 176.4 meters .
BTW ... Jordan may be in trouble. I'm pretty sure it's illegal
in New York City to drop anything off of a tall building.
If someone happens to be walking by the building at that
particular moment, or 6 seconds later, getting hit in the head
by a penny falling at 58.8 m/s (about 132 mph !) can really
smart, and can muss your do for the rest of the day.
Answer:
145 m
Explanation:
Given:
Wavelength (λ) = 2.9 m
we know,
c = f × λ
where,
c = speed of light ; 3.0 x 10⁸ m/s
f = frequency
thus,
substituting the values in the equation we get,
f = 1.03 x 10⁸Hz
Now,
The time period (T) =
or
T = = 9.6 x 10⁻⁹ seconds
thus,
the time interval of one pulse = 100T = 9.6 x 10⁻⁷ s
Time between pulses = (100T×10) = 9.6 x 10⁻⁶ s
Now,
For radar to detect the object the pulse must hit the object and come back to the detector.
Hence, the shortest distance will be half the distance travelled by the pulse back and forth.
Distance = speed × time = 3 x 10^8 m/s × 9.6 x 10⁻⁷ s) = 290 m {Back and forth}
Thus, the minimum distance to target = = 145 m
I think answer is A. The Brightness of a Star