When red litmus paper comes into contact with any alkaline substance, it turns blue. Some examples of alkaline substances are ammonia gas, milk of magnesia, baking soda and limewater.
Answer:
a) The duration, during which the block remain in contact with the spring is 0.29 s
b) The period of the simple harmonic oscillatory motion depends only on the mass and spring constant, therefore when the speed is doubled, the duration of contact remains the same as 0.29 s.
Explanation:
Mass of the block = 465 g
Surface speed = 0.35 m/s
Spring constant , k = 54 N/m
= 0.58 s
a) Since the period for the oscillatory motion is 0.58 s, then the time when the block and spring remain in contact is T/2 = 0.29 s
b) When the speed is doubled, we have

Therefore, since T is only dependent on the mass, m and the spring constant, K, then the time it takes when the speed is doubled remain as
T /2 = 0.29 s
Answer:
The distance travel before stopping is 1.84 m
Explanation:
Given :
coefficient of kinetic friction 
Zak's speed 
Gravitational acceleration

Work done by frictional force is given by,




m
Therefore, the distance travel before stopping is 1.84 m
Answer:
The the quality of the refrigerant at the exit of the expansion valve is 0.179.
Explanation:
Given that,
Initial pressure = 10 bar
Temperature = 22°C
Final pressure = 2.0 bar
We using the value of h

The refrigerant during expansion undergoes a throttling process
Therefore, 
We need to calculate the quality of the refrigerant at the exit of the expansion valve
At 2.0 bar,
The property of ammonia


Using formula

Put the value into the formula



Hence, The the quality of the refrigerant at the exit of the expansion valve is 0.179.