Answer:
b. F1=F2=F3=0 because there is no change in the horizontal motion of the arrows.
Explanation:
The three arrows in the given problem have been shot and it is assumed that air resistance can be neglected. The motions of the arrows are in horizontal direction and as such there is no obvious change in the horizontal motion of the three arrows. Therefore, the three forces are equivalent to one another and each force is equal to zero (i.e. F1=F2=F3=0).
Answer:
The average rate of energy transfer to the cooker is 1.80 kW.
Explanation:
Given that,
Pressure of boiled water = 300 kPa
Mass of water = 3 kg
Time = 30 min
Dryness friction of water = 0.5
Suppose, what is the average rate of energy transfer to the cooker?
We know that,
The specific enthalpy of evaporate at 300 kPa pressure


We need to calculate the enthalpy of water at initial state


We need to calculate the enthalpy of water at final state
Using formula of enthalpy

Put the value into the formula


We need to calculate the rate of energy transfer to the cooker
Using formula of rate of energy

Put the value into the formula


Hence, The average rate of energy transfer to the cooker is 1.80 kW.
Answer:
The maximum speed of the car at the bottom of that drop is 26.34 m/s.
Explanation:
Given that,
The maximum vertical distance covered by the roller coaster, h = 35.4 m
We need to find the maximum speed of the car at the bottom of that drop. It is a case of conservation of energy. The energy at bottom is equal to the energy at top such that :



v = 26.34 m/s
So, the maximum speed of the car at the bottom of that drop is 26.34 m/s. Hence, this is the required solution.
Answer:

Explanation:
The acceleration of an object is given by:

where
v is the final velocity
u is the initial velocity
t is the time interval it takes for the velocity to change from u to v
For the rocket in this problem,
u = 20,000 m/s
v = 24,000 m/s
t = 55.0 - 5.0 = 50.0 s
Substituting,

Answer:
B
Explanation:
because, convection is the transfer of heat between fluid substances/materials