Answer:
The compression is
.
Explanation:
A Hooke's law spring compressed has a potential energy

where k is the spring constant and
the distance to the equilibrium position.
A mass m moving at speed v has a kinetic energy
.
So, in the first part of the problem, the spring is compressed a distance d, and then launch the mass at velocity
. Knowing that the energy is constant.

If we want to double the kinetic energy, then, the knew kinetic energy for a obtained by compressing the spring a distance D, implies:

But, in the left side we can use the previous equation to obtain:





And this is the compression we are looking for
Answer:
momentum of iron ball is greater than wooden ball
Explanation:
when metal ball (iron ball) and wooden drop are drop from same elevation and reaching the ground after same time. at this position the iron ball has greater momentum than wooden ball
we know that momentum is defined as
P=Mv
and we know also that mass of iron ball is greater than mass of wooden ball and they reached on ground at same time and same distance it mean also velocity will be same for both ball. therefore from above relation we have
Miron*V > Mwood*V i.e.
momentum of iron ball is greater than wooden ball
Answer: The volume of an ideal gas will triple in value if the pressure is reduced to one-third of its initial value
Explanation:
We can determine this from the gas laws. Using Boyle's law, which states that "the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature"
Mathematically, P ∝ (1/V)
Since P ∝ (1/V), we can then write that
P = k(1/V)
Where P is the pressure, V is the volume and k is the proportionality constant
PV = k
We can then write that
P1V1 = P2V2 = P3V3 = ...
Hence, P1V1 = P2V2
Where P1 is the initial pressure of the gas
P2 is the final pressure of the gas
V1 is the initial volume of the gas
and V2 is the final volume of the gas
From the question, we want to determine what will make the new volume be thrice the initial volume.
Hence,
P1 = P
V1 = V
P2= ??
V2 = 3V
Therefore,
P × V = P2 × (3V)
P2 = PV/3V
P2 = P/3 = 1/3(P)
This means the volume of an ideal gas will triple in value if the pressure is reduced to one-third of its initial value
Answer: (A) 3.0=A
Explanation: In order to explain this problem we have to use the OHM law, given by: V=R*I
Besides, we have to consider the resitance equivalent for a parallel connection. This is given by:
1/Re=1/R1+1/R2
If we connect the same resistance, the equivalent resistance is R/2.
Initlally the current is 1.5 A when one resistance is connected to the batttery. When a second resistance with the same value is connected in parallel to the battery, we have V=Re*Ifinal= (R/2)*Ifinal
also we know that V=R*Iinitial so Iinitial=V/R
then Ifinal= 2*V/R=2*Iinitial
Answer:
Final distance from the origin: 10.82 km. the vector points as shown in the attached image.
Angle with respect to the east: 
Explanation:
Please refer to the attached image. The cyclist's trip is indicated with the green arrows (9 km to the north followed by 6 km to the east.
So his final position is at the tip of this last vector, and indicated by the orange vector drawn form the point where the trip starts to the cyclist's final location.
We observe that this orange vector is in fact the hypotenuse of a right angle triangle, and we can estimate the distance from the origin by the Pythagorean theorem:

Notice that this is NOT the actual number of km that the cyclist pedaled to reach the final point.
Now, to find the value of the angle
, we need to use trigonometry, and in particular the tangent function gives us the ratio between the side of the triangle "opposite" to the angle, divided the side "adjacent" to the angle:

Now we can find the value of the angle by using the arctan function:
