Answer:
Explanation:
A machine is which no part of the work done on the machine is wasted, is called an ideal or perfect machine
1) A The 78g
2) C Push on the wagon in the opposite direction as Jack with a force that is the same as Jack is applying.
B......................... <span>Yes they do!</span>
Answer:
0.056 miles away
Explanation:
From sound wave,
v = 2x/t .................................. Equation 1
Where v = velocity of sound in air, x = distance of echo, t = time.
making x the subject of the equation,
x = 2v/t........................... Equation 2.
Given: v = 344 m/s, t = 7.6 s.
Substituting into equation 2
x = 2(344)/7.6
x = 90.53 m.
x = 90.53/1609.344
x = 0.056 mile.
Thus the lighting strike 0.056 miles away
Your position at time 
, relative to the stop line:
The Porsche's position:
a. You pass the Porsche immediately after the time it takes for 
:
at which point you both will have traveled 7.8 m from the stop line.
b. The equation in part (a) has two solutions. The Porsche passes you at the second solution of about 
, at which point you both will have traveled 29 m.
c. At time , the Porsche is moving at velocity
so that at the moment it passes you, its speed is 13 m/s, which is about 46.8 km/h and below the speed limit, so neither of you will be pulled over.
