Answer:
V = 3.54 m/s
Explanation:
Using the conservation of energy:
so:
where w is te weigh of kelly, h the distance that kelly decends, m is the mass of kelly and V the velocity in the lowest position.
So, the mass of kelly is:
m = 425N/9.8 = 43.36 Kg
and h is:
h = 1m-0.36m =0.64m
then, replacing values, we get:
Solving for v:
V = 3.54 m/s
Answer: The work done in J is 324
Explanation:
To calculate the amount of work done for an isothermal process is given by the equation:
W = amount of work done = ?
P = pressure = 732 torr = 0.96 atm (760torr =1atm)
= initial volume = 5.68 L
= final volume = 2.35 L
Putting values in above equation, we get:
To convert this into joules, we use the conversion factor:
So,
The positive sign indicates the work is done on the system
Hence, the work done for the given process is 324 J
Answer:
The efficiency of the system is 63.7 %
Explanation:
Given;
input power of the motor, = 1.5 kW = 1,500 W
mass of the car lifted, m = 1300 kg
height through which the car was lifted, h = 1.8 m
time, t = 24 s
The output power of the motor is calculated as;
Output Power = F x v
= (mg) x (d/t)
= (1300 x 9.8) x (1.8 / 24)
= 12,740 x 0.075
= 955.5 W
The efficiency of the system is calculated as;
The correct answer is 63.7%