Answer:
a) a = 2.35 m/s^2
Explanation:
(a) In order to calculate the magnitude of the acceleration of the ball, you use the following formula, for the position of the ball:
(1)
x: position of the ball after t seconds = 87 m
t: time = 8.6 s
a: acceleration of the ball = ?
vo: initial velocity of the ball = 0 m/s
You solve the equation (1) for a:
You replace the values of the parameters in the previous equation:
The acceleration of the ball is 2.35 m/s^2
Answer: Within any frame of reference that is accelerating
Special relativity was proposed on 1905 by Einstein, who developed his theory based on the following two postulates:
1. <em>The laws of physics are the same in all inertial systems. There is no preferential system.
</em>
2. <em>The speed of light in vacuum has the same value for all inertial systems.
</em>
Focusing on the first postulate, it can be affirmed that <u>any measurement on a body is made with reference to the system in which it is being measured</u>.
Now, taking into account that an inertial reference system is the one that complies with the principle of inertia:
<em>"For a body to have acceleration, an external force must act on it."</em>
The correct answer is
Within any frame of reference that is accelerating
Answer:
(a) α = -0.16 rad/s²
(b) t = 33.2 s
Explanation:
(a)
Applying 3rd equation of motion on the circular motion of the tire:
2αθ = ωf² - ωi²
where,
α = angular acceleration = ?
ωf = final angular velocity = 0 rad/s (tire finally stops)
ωi = initial angular velocity = 5.45 rad/s
θ = Angular Displacement = (14.4 rev)(2π rad/1 rev) = 28.8π rad
Therefore,
2(α)(28.8π rad) = (0 rad/s)² - (5.45 rad/s)²
α = -(29.7 rad²/s²)/(57.6π rad)
<u>α = -0.16 rad/s²</u>
<u>Negative sign shows deceleration</u>
<u></u>
(b)
Now, we apply 1st equation of motion:
ωf = ωi + αt
0 rad/s = 5.45 rad/s + (-0.16 rad/s²)t
t = (5.45 rad/s)/(0.16 rad/s²)
<u>t = 33.2 s</u>
Using the formula t=root of 2h/g then where h=28 and g=9.8 then substitute so the answer is 2.4seconds
Answer:42.43m/s
Explanation:According to vf=vi+at, we can calculate it since v0 equals to 0. vf=0+9.8m/s^2*4.33s= 42.434m/s
