Response:
45cm
Clarification:
A converging mirror is generally termed a concave mirror. The focal length and the image distance for a concave mirror are both expressed as positive values.
Using the mirror formula to derive the object distance;
Where f denotes the focal length, u indicates the object distance, and v represents the image distance.
Given f = 30cm, and v = 2u (The formed image is double the size of the pencil)
Plugging these values into the formula to solve for u yields;
By cross-multiplying, we obtain;
2u = 90
Dividing both sides by 2;
2u/2 = 90/2
u = 45cm
The object's distance from the mirror measures 45cm
Answer:
A) and B) are valid.
Explanation:
When an object remains at rest, it is indicative that no net force acts upon it.
The downward gravitational force from Earth must be counterbalanced by an upward force of equal magnitude in order to maintain rest.
This upward force is provided by the normal force, which adjusts to satisfy Newton’s 2nd Law and is always perpendicular to the surface supporting the object (in this instance, the ground).
At the molecular level, this normal force comes from the ground's bonded molecules acting like tiny springs, compressed by the object’s molecules, providing an upward restorative force.
Thus, statements A) and B) are true.
Answer:
option D.
Explanation:
The correct choice is option D.
For an object in equilibrium, the torque measured at any point will be zero.
An object is deemed to be in equilibrium when the net moment acting on it equals zero.
If the object experiences a net moment not equal to zero, it will rotate and will not remain stable.
Response:
83.1946504051 m
Rationale:
u = Starting velocity = 
s = Distance traveled = 
= Incline = 
Friction coefficient
The calculated stopping distance is 83.1946504051 m
Q = mCΔT, in which Q = energy required, m = mass of the block, C = specific heat, ΔT = temperature change.
Utilizing the values provided;
Q = 12*913*(118-20) = 1073688 J = 1073.688 kJ.
The correct option is B.
