In electronics, the SI unit for current is Ampere. It is the amount of charge in Coulombs per unit time. It is named after the father of electrodynamics, Andre-Marie Ampere. Also, the current can be easily determined through the Ohm's Law, which states that current is equal to volts divided by the resistance. The answer is letter D.
Answer:
t = 2 hours
Explanation:
Given that,
Distance of the town, d = 90 miles
Speed, v = 45 mph
We need to find the time to get there. The speed of an object is given by :

Where
t is time

So, the required time is 2 hours.
A hypothesis is a tentative statement which is made to try to explain a known phenomenon but whose truth value is still uncertain, whether it is true or no depends on further research. On the other hand, a theory is made up of hypothesis which have been proven to be true so far, a theory should be able to explain future phenomena successfully
Answer:
the time interval that an earth observer measures is 4 seconds
Explanation:
Given the data in the question;
speed of the spacecraft as it moves past the is 0.6 times the speed of light
we know that speed of light c = 3 × 10⁸ m/s
so speed of spacecraft v = 0.6 × c = 0.6c
time interval between ticks of the spacecraft clock Δt₀ = 3.2 seconds
Now, from time dilation;
t = Δt₀ / √( 1 - ( v² / c² ) )
t = Δt₀ / √( 1 - ( v/c )² )
we substitute
t = 3.2 / √( 1 - ( 0.6c / c )² )
t = 3.2 / √( 1 - ( 0.6 )² )
t = 3.2 / √( 1 - 0.36 )
t = 3.2 / √0.64
t = 3.2 / 0.8
t = 4 seconds
Therefore, the time interval that an earth observer measures is 4 seconds
As per Newton's III law every action has equal and opposite reaction
So here we can say that
every body which apply force on other body must have a reaction force of same magnitude in opposite direction
So here if ball hits the ground by 50 N force then the ball must have a reaction force on itself with same magnitude and opposite direction
the magnitude of the force will be 50 N
and its direction is opposite to the force that ball apply on the floor