Answer:
8 + 2 n (second expression listed)
Explanation:
Since we don't know the number, we represent it with a letter (n).
Twice a number (two times that number) will therefore be: 2 n.
and the addition (sum) of 8 to such will lead to 8 + 2 n
The sum of 8 and twice a number is : 8 + 2 n
The answer is C hope this helps
Answer:
Coefficient of dynamic friction= md= 0.09931
Explanation:
To determine the coefficient of dynamic friction we must first match the friction force that is permendicular to the normal force of the block and opposite to the drag force, to the component of the drag force in this same direction. This component on the X axis of the drag force will be:
F= 90N × cos(30°) = 77.9423N
This component on the X axis of the drag force must be equal to the dynamic friction force that is equal to the coefficient of dynamic friction by the normal force of the block weight:
F= md × m × g= 77.9423N
m= mass of the block
md= coefficient of dynamic friction
g= gravity acceleration
F= md × 80kg× 9.81 (m/s²)= 77.9423(kg×m/s²)
md= (77.9423(kg×m/s²) / 784.8 (kg×m/s²)) = 0.09931
Heat will be transferred from iron to water, because heat flows always from the higher temperature system to the lower temperature system.
