Answer:
Explanation:
A machine is which no part of the work done on the machine is wasted, is called an ideal or perfect machine
Answer:
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
Explanation:
Given;
Mass of car m = 1280kg
initial speed v1 = 92km/h = 92×1000/3600 m/s= 25.56m/s
Final speed v2 = 68km/h = 68×1000/3600 m/s= 18.89m/s
time taken t = 7.5s
Change in the kinetic energy of the car within that period;
∆K.E = 1/2 ×mv1^2 - 1/2 × mv2^2
∆K.E = 0.5m(v1^2 -v2^2)
Substituting the values, we have;
∆K.E = 0.5×1280(25.56^2 - 18.89^2)
∆K.E = 189748.16J
Power used during this Change;
Power P = ∆K.E/t
Substituting the values;
P = 189748.16/7.5
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
<span>I don't think there is enough information from the question. If you are asked to calculate the number of microbes in a certain area., then it should be that the total area or maybe the volume of that should be given so you can estimate the number of microbes. Hope this helps.</span>
