The following choice that is NOT a way that machines provides a mechanical advantage is to change direction. The correct answer is A.
A. Impulse is simply the product of Force and time.
Therefore,
I = F * t --->
1
where I is impulse, F is force, t is time
However another formula for solving impulse is:
I = m vf – m vi --->
2
where m is mass, vf is final velocity and vi is initial
velocity
Therefore using equation 2 to solve for impulse I:
I = 2000kg (0) – 2000kg (77 m/s)
I = -154,000 kg m/s
B. By conservation of momentum, we also know that Impulse
is conserved. That means that increasing the time by a factor of 3 would still
result in an impuse of -154,000 kg m/s. So,
I = F’ * (3 t) = -154,000 kg m/s
Since t is multiplied by 3, therefore this only means
that Force is decreased by a factor of 3 to keep the impulse constant,
therefore:
(F/3) (3t) = -154,000 kg m/s
Summary of Answers:
A. I = -154,000 kg m/s
B. Force is decreased by factor of 3
Answer:
The horizontal distance traveled when the stone returns to its original height = 220.81 m
Explanation:
Considering vertical motion of catapult:-
At maximum height,
Initial velocity, u = 50 sin30 = 25 m/s
Acceleration , a = -9.81 m/s²
Final velocity, v = 0 m/s
We have equation of motion v = u + at
Substituting
v = u + at
0 = 25 - 9.81 x t
t = 2.55 s
Time of flight = 2 x Time to reach maximum height = 2 x 2.55 = 3.1 s
Considering horizontal motion of catapult:-
Initial velocity, u = 50 cos30 = 43.30 m/s
Acceleration , a = 0 m/s²
Time, t = 5.10 s
We have equation of motion s= ut + 0.5 at²
Substituting
s= ut + 0.5 at²
s = 43.30 x 5.10 + 0.5 x 0 x 5.10²
s = 220.81 m
The horizontal distance traveled when the stone returns to its original height = 220.81 m
Answer:
Particle spacing increases and it's called evaporating