Since we have 15 kilometers per hour, and we're looking for 20 minutes, let's set up proportions.
20/60 minutes = x/15
20/60 = 1/3, so let's leave that simplified.
1/3 = x/15
Look at the denominators, 3 to 15 is a factor of 5, so multiply the numerator by 5.
1 • 5 = 5, so you will cover 5 kilometers in 20 minutes.
I hope this helps!
Answer:
(a) Heat transfer to the environment is: 1 MJ and (b) The efficiency of the engine is: 41.5%
Explanation:
Using the formula that relate heat and work from the thermodynamic theory as:
solving to Q_out we get:
this is the heat out of the cycle or engine, so it will be heat transfer to the environment. The thermal efficiency of a Carnot cycle gives us: 
where T_Low is the lowest cycle temperature and T_High the highest, we need to remember that a Carnot cycle depends only on the absolute temperatures, if you remember the convertion of K=°C+273.15 so T_Low=150+273.15=423.15 K and T_High=450+273.15=723.15K and replacing the values in the equation we get:
Answer:
192000 J or 192 kJ
Explanation:
Work done = Force × distance moved along the direction of force.
From the question,
W = F×d............... Equation 1
Where W = work done by the car, F = Force of the car, d = distance move by the car along the direction of the force.
We can calculate for d using the equation of motion
d = (v+u)t/2..................... Equation 2
Where v = Final velocity of the car, u = Initial velocity of the car, t = time.
Given: u = 12 m/s, v = 0 m/s(skids to a stop), t = 4.0 s
Substitute into equation 2
d = (12+0)4/2
d = 24 m.
Also given: F = 8000 N
Substitute into equation 1
W = 8000×24
W = 192000 J
W = 192 kJ.
What is the speed of a wave if it is 8 meters long and has a frequency if 3 hz?
the answer is 24 m/s
