The mass of the aeroplane is 300,000 kg.
<h3>What is Newton's second law of motion?</h3>
It states that the force F is directly proportional to the acceleration a of the body and its mass.
The law is represented as
F =ma
where acceleration a = velocity change v / time interval t
Given is the aeroplane lands at a speed of 80 m/s. After landing, the aeroplane takes 28 s to decelerate to a speed of 10 m/s. The mean resultant force on the aeroplane as it decelerates is 750 000 N.
The force expression will be
F = mv/t
Substitute the values and we have
750000 = m x (80 -10)/ 28
750,000 = m x 2.5
m = 300,000 kg
Thus, the mass of the aeroplane is 300,000 kg.
Learn more about Newton's second law of motion.
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Answer:
μ = 0.309
Explanation:
coefficient of kinetic friction is defined as the ratio of two forces, friction force and the normal force acting on the object.
θ = arctan(15/100)= 8.531⁰
In the vertical direction:
N = mgcosθ = 100 *9.8 *cos(8.531) = 970N
law of conservation of energy implies
mgsinθ - μNx = 1/2m(v₂²-v₁²)
100*9.8*sin (8.531) - μ(970*2) = 1/2(100)(0²-3²)
150.6 - 1940μ = 450
- 1940μ = -600.6
μ = 0.309
During convection of air currents, cool air sinks. <em>(b)</em>
The answer is B
explanation