PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!! Which represents the smallest number?
2 answers:
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- Initial velocity=0m/s=u
- Acceleration=a=5.5m/s^2
#8.1
- t=12s
#8.2
- u=0m/s
- v=18m/s
- a=5.5m/s^2
Use third equation of kinematics
Answer:
Maximum shearing force developed in each of the two pegs during acceleration is 1830 lbf
Explanation:
First we will find the acceleration of pickup truck.
As, the acceleration is uniform, therefore we can use Newton's third equation of motion:
2as =
First convert speed into ft/sec
1 mile/hr = 1.47 ft/sec
therefore,
37 mile/hr = 37 x 1.47 ft/sec
37 mile/hr = 54.39 ft/sec
with initial speed 0 ft/sec (starting from rest), using in equation of motion:
a = [(54.39 ft/sec)² - (0 ft/sec)²]/2(215 ft)
a = 6.88 ft/sec²
Now, the total shear force will be given by Newton's second law of motion:
F = ma
F = (460 lbm +72 lbm)(6.88 ft/sec²)
F = 3660 lbf
Now for the max shear force in each of the two pegs we divide total fore by 2:
Force in each peg = F/2 = (3660 lbf)/2
<u>Force in each peg = 1830 lbf</u>
Answer:
His pitching speed is 38 m/s.
Explanation:
Hi there!
Please see the attached figure for a better understanding of the problem.
The position of the ball at any time t is given by the following vector:
r = (x0 + v0 · t, y0 + 1/2 · g · t²)
Where:
r = position vector of the ball at time t.
x0 = initial horizontal position.
v0 = initial horizontal velocity.
t = time.
y0 = initial vertical position.
g = acceleration due to gravity (-9.8 m/s² considering the upward direction as positive).
Let's place the origin of the frame of reference at the throwing point so that x0 and y0 = 0.
When the ball reaches the ground, its position vector will be r1 (see figure). Using the equation of the vertical component of the position vector, we can find the time at which the ball reaches the ground. At that time, the horizontal component of the position is 30 m and the vertical component is -3.0 m (see figure):
y = y0 + 1/2 · g · t² (y0 = 0)
y = 1/2 · g · t²
-3.0 m = 1/2 · (-9.8 m/s²) · t²
-3.0 m / -4.9 m/s² = t²
t = 0.78 s
Now, knowing that at this time x = 30 m, we can find v0:
x = x0 + v0 · t (x0 = 0)
x = v0 · t
30 m = v0 · 0.78 s
v0 = 30 m / 0.78 s
v0 = 38 m/s
His pitching speed is 38 m/s.
