From my experience, I would say it is true.
Answer:
Explanation:
Given a ball of mass m= 0.5kg
The ball moves in as circle of radius r= 0.4m
Speed of the ball is v = 4m/s
Centripetal force is exerted on ball and it is given as
Fc = m•ac
ac is centripetal acceleration and it is given as
ac = v²/r
Then,
Fc = mv²/r
Fc = 0.5 × 4²/0.4
Fc = 20N.
The force exerted on the ball is 20N
The solubility of gases in liquids increases with the increase in pressure.
Answer: 
Explanation:
Given
Charge discharged 
time taken 
Current is given as rate of change of discharge i.e.

Therefore, the average current is 
Answer:
The amount of kilograms of ice at -20.0°C that must be dropped into the water to make the final temperature of the system 40.0°C = 0.0674 kg
Explanation:
Heat gained by ice in taking the total temperature to 40°C = Heat lost by the water
Total Heat gained by ice = Heat used by ice to move from -20°C to 0°C + Heat used to melt at 0°C + Heat used to reach 40°C from 0°C
To do this, we require the specific heat capacity of ice, latent heat of ice and the specific heat capacity of water. All will be obtained from literature.
Specific heat capacity of ice = Cᵢ = 2108 J/kg.°C
Latent heat of ice = L = 334000 J/kg
Specific heat capacity of water = C = 4186 J/kg.°C
Heat gained by ice in taking the total temperature to 40°C = mCᵢ ΔT + mL + mC ΔT = m(2108)(0 - (-20)) + m(334000) + m(4186)(40 - 0) = 42160m + 334000m + 167440m = 543600 m
Heat lost by water = mC ΔT = 0.25 (4186)(75 - 40) = 36627.5 J
543600 m = 36627.5
m = 0.0674 kg = 67.4 g of ice.