The heat remains constant because there’s nothing to cool it down
Answer:
<h3>After 3seconds</h3>
Explanation:
A supersonic aircraft flies at 3 km altitude at a speed of 1000 m/s on a standard day. How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer
Using the formula for calculating speed expressed as;
Speed = Distance/Time
Given;
Distance = 3km = 3000m
Speed = 1000m/s
Required
How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer (Time)
From the formula;
Time = Distance/speed
Time = 3000/1000
Time = 3seconds
Hence the sound of the aircraft is heard after 3 seconds
Answer:
People can hear sounds at frequencies from about 20 Hz to 20,000 Hz,
Answer: 5 km/hr
Explanation:
speed= distance divided by time
20/4
= 5 km/hr
Answer: 45.3°
Explanation:
Given,
Length of ladder = l
Weight of ladder = w
Coefficient of friction = μs = 0.495
Smallest angle the ladder makes = θ
If we assume the forces in the vertical direction to be N1, and the forces in the horizontal direction to be N2, then,
N1 = mg and
N2 = μmg
Moment at a point A in the clockwise direction is
N2 Lsinθ - mg.(L/2).cosθ = 0
μmgLsinθ - mg.(L/2).cosθ = 0
μmgLsinθ = mg.(L/2).cosθ
μsinθ = cosθ/2
sin θ / cos θ = 1 / 2μ
Tan θ = 1 / 2μ
Substituting the value of μ = 0.495, we have
Tan θ = 1 / 2 * 0.495
Tan θ = 1 / 0.99
Tan θ = 1.01
θ = tan^-1(1.01)
θ = 45.3°
