I believe the correct answer is atmosphere (D).
Answer:
a)1815Joules b) 185Joules
Explanation:
Hooke's law states that the extension of a material is directly proportional to the applied force provided that the elastic limit is not exceeded. Mathematically;
F = ke where;
F is the applied force
k is the elastic constant
e is the extension of the material
From the formula, k = F/e
F1/e1 = F2/e2
If a force of 60N causes an extension of 0.5m of the string from its equilibrium position, the elastic constant of the spring will be ;
k = 60/0.5
k = 120N/m
a) To get the work done in stretching the spring 5.5m from its position,
Work done by the spring = 1/2ke²
Given k = 120N/m, e = 5.5m
Work done = 1/2×120×5.5²
Work done = 60× 5.5²
Work done = 1815Joules
b) work done in compressing the spring 1.5m from its equilibrium position will be gotten using the same formula;
Work done = 1/2ke²
Work done =1/2× 120×1.5²
Works done = 60×1.5²
Work done = 135Joules
Let's start by using the mirror equation:

where f=10 cm is the focal lenght of the mirror, d=38 cm is the distance of the object from the mirror, while q is the distance of the image from the mirror.
For the sign convention, f is taken as positive for a concave mirror. Therefore, we can solve the equation for q:

from which we find q=13.6 cm.
The fact that q is positive means that the image is
real, so it is on the same side of the object, with respect to the mirror.
Then we can also find the size of the image with respect to the original object. The magnification is given by

The negative sign means that the image is
inverted, and the size of the image is 0.36 times the size of the object.
A. The fly's velocity to the ground is less than the car's velocity to the ground.
Answer:
The angular momentum of a cylinder, when it is rotating with constant angular velocity is Lini =Iωi
. When two cylinders are added to the rotating cylinder, which are identical in their dimensions, the moment of inertia of the entire system increases (since mass increases). The final moment of inertia will be 3I
Since friction exist, all the cylinders start rotating with same angular velocity, the new angular velocity can be calculated using conservation of angular momentum
Thus, Iωi =3Iωf ⟹ωf =ωi/3 = 0.33ωi