Answer:
The primary reason of seeing the cracker burst and hearing the sound later is because the speed of sound and light. Speed of light is in the vicinity of 3*10^8m,/ sec while the speed of sound is at a distance of 332m/sec. It is similar to lightning that strikes before the sound.
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Answer:
11.7 m
Explanation:
I assume north is the y direction and x is the east direction, so Δx refers to the displacement in the east direction.
First, find the time it takes for the velocity to change from directly north to directly east.
Given (in the y direction):
v₀ = 2.88 m/s
v = 0 m/s
a = 0.350 m/s² sin(-52.0°) = -0.276 m/s²
Find: t
v = at + v₀
(0 m/s) = (-0.276 m/s²) t + (2.88 m/s)
t = 10.4 s
Given (in the x direction):
v₀ = 0 m/s
a = 0.350 m/s² cos(-52.0°) = 0.215 m/s²
t = 10.4 s
Find: Δx
Δx = v₀ t + ½ at²
Δx = (0 m/s) (10.4 s) + ½ (0.215 m/s²) (10.4 s)²
Δx = 11.7 m
Answer:
B. Electrons are transferred from the fur to the plastic rod.
Explanation:
Triboelectricity or friction charging refers to the ability of materials to gain or lose electrons as a result of rubbing them against something. This phenomenon has been observed in the case of rubbing plastic rod against fur, or glass rod against silk.
In the context of rubbing plastic rod against fur, what happens is that the fur which has an excess of charges loses electrons to the plastic rod. This makes the plastic rod to become positively charged, and the fur, negatively charged.
Answer:
a)0.0229 m
b)0.393 rad
c)1.57
d)707.6 N
e)0.298 m/s
Explanation:
Given:
- Mass of the machine, m=70 kg
- Stiffness of the system, k=30000 N/m
- Damping ratio=0.2
- Damping force, F=450 N
- Angular velocity
a)We know that the amplitude X at steady state is given by
Where
![X=\dfrac{\dfrac{450}{70}}{\sqrt{20.7^2-13^2)^2 +(2\times 0.2\times20.7\times13)^2}}\\[tex]X=0.0229\ \rm m](https://tex.z-dn.net/?f=X%3D%5Cdfrac%7B%5Cdfrac%7B450%7D%7B70%7D%7D%7B%5Csqrt%7B20.7%5E2-13%5E2%29%5E2%20%2B%282%5Ctimes%200.2%5Ctimes20.7%5Ctimes13%29%5E2%7D%7D%5C%5C%5Btex%5DX%3D0.0229%5C%20%5Crm%20m)
b) The phase shift of the motion is given by
c)Transmissibility ratio is given by
d)The magnitude of the force transmitted to the ground is
e)The maximum velocity is given by 
Answer:
Maximum height of the ball, h(t) = 27.56 m
Explanation:
It is given that, a ball is shot from the ground straight up into the air with initial velocity of 42 ft/sec.
The height of the ball as a function of time t is given by :
h₀ is initial height, h₀ = 0
So, 
.........(1)
For maximum/minimum height, 
...(2)
t = 1.31 s
Differentiating equation (2) wrt t
h''(t) = -32 < 0
So, at t = 1.31 seconds we will get the maximum height.
Put the value of t in equation (1)
h(t) = 27.56 m
Hence, this is the required solution.
