A car moves along an x axis through a distance of 900 m, starting at rest (at x = 0) and ending at rest (at x = 900 m). Through the first 1/4 of that distance, its acceleration is +6.25 m/s2. Through the next 3/4 of that distance, its acceleration is -2.08 m/s2. What are (a) its travel time through the 900 m and (b) its maximum speed?
<span>Solve for the time at the 1/4 mark. That's 225 m. How? d = (1/2)at^2 ( initial velocity zero). Thus 225 = (1/2) 6.25 t^2. t^2 = ( 225 * 2 ) / 6.25. t = 8.5 sec. </span>
<span>At the other end t^2 = (675 * 2) / 2.08 -- we reversed the sign and ran time backwards. t = 25.5 sec. </span>
<span>So total time is 8.5 + 25.5 or 34 sec. </span>
<span>Since zero initial velocity: v^2 = 2 a d. Here, v^2 = 2 * 6.25 * 225. v = 53 m/s. That's the fastest speed since braking then occurs.</span>
Answer:
(a) Fₓ = 0 N
= 9.08 N
(b)
(a) Fₓ = 0 N
<u></u>
= 9.08 N
(c)
= 0 N
Fₓ = 9.08 N
Explanation:
The magnitude of the force will remain the same in each case, which is given as follows:
F = ma (Newton's Second Law)
where,
F = force = ?
m = mass = 4.54 kg
a = acceleration = 2 m/s²
Therefore,
F = (4.54 kg)(2 m/s²)
F = 9.08 N
Now, we come to each scenario:
(a)
Since the motion is in the vertical direction. Therefore the magnitude of the force in x-direction will be zero:
<u>Fₓ = 0 N</u>
For upward direction the force will be positive:
<u></u>
<u> = 9.08 N</u>
<u></u>
(b)
Since the motion is in the vertical direction. Therefore the magnitude of the force in x-direction will be zero:
<u>Fₓ = 0 N</u>
For upward direction the force will be negative:
<u></u>
<u> = - 9.08 N</u>
<u></u>
(c)
Since the motion is in the horizontal direction. Therefore the magnitude of the force in y-direction will be zero:
<u></u>
<u> = 0 N</u>
<u>Fₓ = 9.08 N</u>
Let
a = acceleration.
v = Speed
r = position
t = time.
To find the answer, you must write the equations of speed, and position known and clear the variables that are needed to find the acceleration.
The answer is a = 7.98m / s ^ 2.
I attach the solution.
Answer:
The correct answer is:
(a) 84.240 kg
(b) 24.038 m
Explanation:
The given values are:
Force,
F = 81.0 N
Distance,
S = 13.0 m
Time,
t = 5.20 s
As we know,
The acceleration of mass will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
⇒ 
(a)
The mass of the block will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
(b)
The final velocity after a given time i.e.,
t = 5.00 s
⇒ 
On substituting the values, we get
⇒ 
⇒ 
In time, t = 5.00 s
The distance moved by the block will be:
⇒ 
On putting the values, we get
⇒ 
⇒ 
If the conductor isn't working it would be blocked