Explanation:
time spent to run from house to school=100/5=20s
time spent to return from school=100/10=10s
average velocity=200m/(10+20)
Answer:
60 m/s
Explanation:
From the law of conservation of energy,
The kinetic energy of the plane = Energy of store in the spring when the plane lands.
1/2mv² = 1/2ke²
making v the subject of the equation.
v = √(ke²/m).................... Equation 1
Where v = the plane landing speed, k = spring constant, e = extension. m = mass of the plane.
Given: m = 15000 kg, k = 60000 N/m, e = 30 m.
Substitute into equation 1
v = √(60000×30²/15000)
v = √(4×900)
v = √(3600)
v = 60 m/s.
Hence the plane's landing speed = 60 m/s
<span>Δ</span>E = q + w
q = heat (quantity of)
q and w can be positive or negative depending on if work/heat is being absorbed/done on the system or released/done by the system
