A single fixed pulley can be used to raise or lower lightweight objects.
Option b
<u>Explanation:</u>
A pulley is a simple machine tool which is used to make lifting or lowering tasks easy. A single fixed pulley is a system involving only one pulley fixed on a constant rigid support with a rope wrapped around the wheel. Such a system can be used only to change the direction of applied force in raising or lowering small, lightweight objects which need minimal work force.
A single fixed pulley system helps only in redirecting the applied force direction by using a rope and wheel assembly. The work done in such a case remains the same and hence it is not preferred to use it in lifting heavy objects. Neither is the required force reduced in case of a single fixed pulley system. A movable pulley helps in achieving (A) and (C).
Answer:
Volume will increase by factor 2
So option (A) will be correct answer
Explanation:
Let initially the volume is V pressure is P and temperature is T
According to ideal gas equation 
, here n is number of moles and R is gas constant
So 
....................eqn 1
Now pressure is doubled and temperature is quadrupled
So new volume 
........eqn 2
Now comparing eqn 1 nad eqn 2
So volume will increase by factor 2
So option (A) will be correct answer
<span>a decrease in the distance between the earth and the moon</span>
Answer:
45.8 cm
Explanation:
To solve this, we will use the formula
5 / x² = 7/(1 - x)²
5 / x² = 7 / (1 - 2x + x²)
5 / 7 = x² / (1 - 2x + x²)
x = 0.5 * (√(35) - 5) meters
x = 0.5 * (5.916 - 5)
x = 0.5 * (0.916)
x = 0.458 or x = 45.8
