Answer:
e = 0.46 m
Explanation:
From the laws of friction, frictional force, F is proportional to normal reaction, R.
F₁ = μR
where μ is coefficient of friction; R = mg and g = 9.8 ms⁻²
Also, from Hooke's law, extension, e, in an elastic spring is proportional to applied force.
F₂ = Ke
where K is force constant of the spring
Since the box is just about to move, the coefficient of friction involved is static friction.
The force on the spring equals the frictional force experienced by the box the box; F₁ = F₂
Ke = μR
e = μR/K
where μ = 0.65; R = 18 kg * 9.8 ms⁻²; K = 250 N/m
e = (0.65 * 18 * 9.8)/250
e = 0.46 m
Answer:
Gravity Increases - Mass increases, distance decreases
Gravity Decreaes - Mass decreases, distance increases
Answer:
-19.259m/s
Explanation:
Given;
Final velocity = 19m/s
time t = 1.6s
u is the initial velocity
g is the acceleration due to gravity = 9.81m/s²
Using the equation of motion to first get the initial velocity of the shell:
v = u-gt
19 = u - (9.81)(1.6)
19 = u - 15.696
u = 19+15.696
u = 34.696m/s
The initial velocity of the shell is 34.696m/s
Next is to find the speed of the shell 5.5s after the launch
Using the equation of motion:
v = u-gt
v = 34.696-9.81(5.5)
v = 34.696 - 53.955
v = -19.259m/s
<em>The negative value of the velocity shows that the velocity is travelling in the downward direction</em>
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In a balanced system, the total energy should always stay the same. The total energy is the sum of the potential and the kinetic energies. If the potential energy increases, then the kinetic energy should decrease. This happens to keep the system under a state of balance.
The answer is C because the north pole of the magnet in the south pole of the magnet the move together