Answer:
a) t = 2.0 s, b) x_f = - 24.56 m, Δx = 16.56 m
Explanation:
This is an exercise in kinematics, the relationship of position and time is indicated
x = 5 t³ - 9t² -24 t - 8
a) ask when the velocity is zero
speed is defined by
v = 
let's perform the derivative
v = 15 t² - 18t - 24
0 = 15 t² - 18t - 24
let's solve the quadratic equation
t = 
t1 = -0.8 s
t2 = 2.0 s
the time has to be positive therefore the correct answer is t = 2.0 s
b) the position and distance traveled for a = 0
acceleration is defined by
a = dv / dt
a = 30 t - 18
a = 0
30 t = 18
t = 18/30
t = 0.6 s
we substitute this time in the expression of the position
x = 5 0.6³ - 9 0.6² - 24 0.6 - 8
x = 1.08 - 3.24 - 14.4 - 8
x = -24.56 m
we see that all the movement is in one dimension so the distance traveled is the change in position between t = 0 and t = 0.6 s
the position for t = 0
x₀ = -8 m
the position for t = 0.6 s
x_f = - 24.56 m
the distance
ΔX = x_f - x₀
Δx = | -24.56 -(-8) |
Δx = 16.56 m
<span>Product can be defined as a thing or person that is the result of an action or process</span>
Answer: B
The forklift is doing positive work on the object because the direction of force and the direction of motion are the same. The force of gravity is doing negative work on the object because it is acting opposite to the direction of motion.
Explanation: The work done in lifting an object up is positive when the direction of the displacement and the force applied are in the same direction.
The work will be negative if force and direction of the motion are opposite to each other.
Also, force of gravity is considered positive when an object is moving toward the gravity. That is coming downward. Otherwise, it's negative when it's moving in the opposite direction.
When a forklift raises an object, the forklift is doing positive work on the object because the direction of force and the direction of motion are the same. The force of gravity is doing negative work on the object because it is acting opposite to the direction of motion.
Answer:
The separation distance between the two charges must be 82704.2925 m
Explanation:
Given:
Two negative charges that are both q = -3.8 C
Force of 19 N
Question: How far apart are the two charges, s = ?
First, you need to get the electrostatic force of this two negative charges:
Here
k = electric constant of the medium = 9x10⁹N m²/C²
Substituting values:
