Give an example of Newton's second law in everyday life?
1 answer:
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Answer:
the average speed of the car is 170 mph.
Explanation:
Given;
initial speed, u = 70 mph
time of motion, t₁ = 3 hours
final speed, v = 20 mph
time of motion, t₂ = 2 hours
The average speed of the car is calculated as;
Therefore, the average speed of the car is 170 mph.
The correct answer is
B It increases.
In fact, the kinetic energy of a moving object is given by
where m is the mass of the object and v is its speed. We see that the kinetic energy is proportional to the mass and proportional to the square of the speed: in this problem, the speed of the object remains the same, while its mass increases, therefore the kinetic energy will increase as well.
B It increases.
In fact, the kinetic energy of a moving object is given by
where m is the mass of the object and v is its speed. We see that the kinetic energy is proportional to the mass and proportional to the square of the speed: in this problem, the speed of the object remains the same, while its mass increases, therefore the kinetic energy will increase as well.
Answer:
<em>2.78m/s²</em>
Explanation:
Complete question:
<em>A box is placed on a 30° frictionless incline. What is the acceleration of the box as it slides down the incline when the co-efficient of friction is 0.25?</em>
According to Newton's second law of motion:
Where:
is the coefficient of friction
g is the acceleration due to gravity
Fm is the moving force acting on the body
Ff is the frictional force
m is the mass of the box
a is the acceleration'
Given
Required
acceleration of the box
Substitute the given parameters into the resulting expression above:
Recall that:
9.8sin30 - 0.25(9.8)cos30 = ax
9.8(0.5) - 0.25(9.8)(0.866) = ax
4.9 - 2.1217 = ax
ax = 2.78m/s²
<em>Hence the acceleration of the box as it slides down the incline is 2.78m/s²</em>