Suppose a rock is dropped off a cliff with an initial speed of 0m/s. What is the rocks speed after 5 secounds, in m/s, if it enc
2 answers:
You might be interested in
Answer:
None, both objects will hit ground at the same time.
Explanation:
- Assuming no air resistance present, and that both objects start from rest, we can apply the following kinematic equation for the vertical displacement:
- As the left side in (1) is the same for both objects, the right side will be the same also.
- Since g is constant close to the surface of the Earth, it's also the same for both objects.
- So, the time t must be the same for both objects also.
Answer:
(a) α = 35.20 rad/s^2
(b) θ = 802°
(c) v = 139.73 cm/s
(d) a = 156.64 cm/s^2
Explanation:
(a) To find the angular acceleration of the disc you use the following formula:
(1)
w: angular speed of the disc = 31.4 rad/s
wo: initial angular speed = 0 rad/s
t: time = 0.892s
You replace the values of the parameters in the equation (1):
The angular acceleration of the disc, for the given time, is 35.20rad/s^2
(b) To calculate the angle describe by the disc in such a time you use:
(2)
In degrees you have:
The angle described by the disc is 802°
(c) To calculate the tangential speed of the microbe for t=0.892s, you use the following formula:
(3)
w: angular speed for t = 0.892s = 31.4rad/s
r: radius of the disc = 4.45cm
The tangential speed is 139.73 cm/s
(d) The tangential acceleration is calculated by using the following formula:
α: angular acceleration for t=0.892s
The tangential acceleration is 156.64cm/s^2