Answer:
Initial kinetic energy will be 2608200 lbf-ft
Initial speed will be 240.7488 m/sec
Explanation:
We have given height h = 900 ft
Mass of the object m = 90 lbm
Acceleration due to gravity
Initial kinetic energy will be equal to potential energy of the object
So kinetic energy = potential energy = mgh
This energy is also equal to the initial kinetic energy
So
So initial velocity will be 240.7488 m/sec
Answer:
The coefficient of friction is (F/(19.6·m)
Explanation:
The given parameters are;
The force applied to the immovable body = F
The time duration the force acts = t
The time the body spends in motion = 3·t
The acceleration due to gravity, g = 9.8 m/s²
From Newton's second law of motion, we have;
The impulse of the force = F × t = m × Δv₁
Where;
Δv₁ = v₁ - 0 = v₁
The impulse applied by the force of friction, is
× (3·t - t) =
× (2·t)
Given that the motion of the object is stopped by the frictional force, we have;
The impulse due to the frictional force = Momentum change = m × Δv₂ = × (2·t)
Where;
Δv₂ = v₂ - 0 = v₂
Given that the velocity, v₂, at the start of the deceleration = The velocity at the point the force ceased to act, v₁, we have;
m × Δv₂ = × (2·t) = m × Δv₁ = F × t
∴ × (2·t) = F × t
= F × t/(2·t) = F/2
The coefficient of dynamic friction, = Frictional force/(The weight of the body) = (F/2)/(9.8 × m)
= (F/(19.6·m)
The coefficient of friction, = (F/(19.6·m)
Answer:
the Power required is 300 W
Explanation:
We know that the definition of work is given by the following expresion:
the distance is 1.5 meters and the Force is equal to 1000 N.
Replacing this values in the work expresion
And the power is equal to the amount of work done in a given time, therefore we have:
Time in seconds