Answer:
Final temperature of the aluminum = 41.8 °C
Explanation:
We have the equation for energy
E = mcΔT
Here m = 55 g = 0.055 kg
ΔT = T - 27.5
Specific heat capacity of aluminum = 921.096 J/kg.K
E = 725 J
Substituting
E = mcΔT
725 = 0.055 x 921.096 x (T - 27.5)
T - 27.5 = 14.31
T = 41.81 ° C = 41.8 °C
Final temperature of the aluminum = 41.8 °C
Given parameters:
Displacement = 8km
Velocity = 3.8km/h
Unknown:
time = ?
Solution:
Velocity is displacement divided by time.
Velocity = 
Displacement = velocity x time
Input the parameters:
8 = 3.8 x time
Time = 
= 2.1s
The time taken is 2.1s
Answer:
40 Hz
Explanation:
f = 1/T = 1 / 0.025 = 40 Hz
Steps 1 and 2)
The variables are W = work, P = power, and t = time. In this case, W = 9514 joules and P = 347 watts.
The goal is to solve for the unknown time t.
-----------------------
Step 3)
Since we want to solve for the time, and we have known W and P values, we use the equation t = W/P
-----------------------
Step 4)
t = W/P
t = 9514/347
t = 27.4178674351586
t = 27.4 seconds
-----------------------
Step 5)
The lawn mower ran for about 27.4 seconds. I rounded to three sig figs because this was the lower amount of sig figs when comparing 9514 and 347.
-----------------------
Note: we don't use the mass at all
