Answer:
(A) Reading will be 65 N
(B) Net force on the elevator will be 49.076 N
Explanation:
We have given the balance force = 65 N
Acceleration due to gravity 
We know that W=mg
So 
m = 6.632 kg
(a) In first case as the as the speed is constant so the force on the elevator will be 65 N
(B) In second case as the elevator is decelerating at a rate of 
So net acceleration = 9.8-2.4=
So net force on elevator will be = m× net acceleration = 6.632×7.4 = 49.076 N
Answer:
Thats her fault.........................b
Explanation:
Answer:the answer is B
Explanation: just took the quiz
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.
Answer:
Explanation:
Kinetic energy generated = work done by force = force x displacement
= 3 x 7 = 21 J
