Answer:
2.73414 seconds
467622.66798 J
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
g = Acceleration due to gravity = 9.81 m/s² = a



or

The time taken is 2.73414 seconds
The potential energy is given by

The change in potential energy is 467622.66798 J
Answer:
The speed of the block is 4.96 m/s.
Explanation:
Given that.
Mass of block = 1.00 kg
Spring constant = 500 N/m
Position 
Coefficient of friction = 0.350
(A). We need to calculate the speed the block has as it passes through equilibrium if the horizontal surface is friction less
Using formula of kinetic energy and potential energy

Put the value into the formula




Hence, The speed of the block is 4.96 m/s.
<span>Electric field is proportional to q/d^2, where q is the magnitude of the charge and d is the distance. Since all the given units are identical, we can just compare their relative magnitudes without calculating for the exact values.
A) 3/(0.4)^2 = 18.75
B) 1.5/(0.2)^2 = 37.5
C) 6/(0.4)^2 = 37.5
D) 3/(0.2)^2 = 75
Therefore, choice D has the largest electric field of all.
</span>
To solve this problem we will use the linear motion description kinematic equations. We will proceed to analyze the general case by which the analysis is taken for the second car and the tenth. So we have to:

Where,
x= Displacement
= Initial velocity
a = Acceleration
t = time
Since there is no initial velocity, the same equation can be transformed in terms of length and time as:

For the second cart

When the tenth car is aligned the length will be 9 times the initial therefore:

When the tenth car has passed the length will be 10 times the initial therefore:

The difference in time taken from the second car to pass it is 5 seconds, therefore:

From the first equation replacing it in the second one we will have that the relationship of the two times is equivalent to:


From the relationship when the car has passed and the time difference we will have to:



Replacing the value found in the equation given for the second car equation we have to:

Finally we will have the time when the cars are aligned is


The time when you have passed it would be:


The difference between the two times would be:

Therefore the correct answer is C.
Answer:
0.4 ohms.
Explanation:
From the circuit,
The voltage reading in the voltmeter = voltage drop across each of the parallel resistance.
1/R' = 1/R1+1/R2
R' = (R1×R2)/(R1+R2)
R' = (2.4×1.2)/(2.4+1.2)
R' = 2.88/3.6
R' = 0.8 ohms.
Hence the current flowing through the circuit is
I = V'/R'................ Equation 1
Where V' = voltmeter reading
I = 6/0.8
I = 7.5 A
This is the same current that flows through the variable resistor.
Voltage drop across the variable resistor = 9-6 = 3 V
Therefore, the resistance of the variable resistor = 3/7.5
Resistance = 0.4 ohms.