<h2>
The magnitude 24 (
) of the acceleration of the particle when the particle is not moving.</h2>
Explanation:
Given,
A particle moving along the x-axis has a position given by
m ........ (1)
To find, the magnitude (
) of the acceleration of the particle when the particle is not moving = ?
Differentiating equation (1) w.r.t, 't', we get
![\dfrac{dx}{dt} =\dfrac{d((24t-2.0t^3))}{dt}](https://tex.z-dn.net/?f=%5Cdfrac%7Bdx%7D%7Bdt%7D%20%3D%5Cdfrac%7Bd%28%2824t-2.0t%5E3%29%29%7D%7Bdt%7D)
⇒
....... (2)
⇒ ![24-6t^{2} = 0](https://tex.z-dn.net/?f=24-6t%5E%7B2%7D%20%3D%200)
⇒ ![t^{2}=2^{2}](https://tex.z-dn.net/?f=t%5E%7B2%7D%3D2%5E%7B2%7D)
⇒ t = 2 s
Again, differentiating equation (2) w.r.t, 't', we get
![\dfrac{d^2x}{dt^2} =-12t](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5E2x%7D%7Bdt%5E2%7D%20%3D-12t)
Put t = 2, we get
![\dfrac{d^2x}{dt^2} =-12(2)=24](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5E2x%7D%7Bdt%5E2%7D%20%3D-12%282%29%3D24)
Thus, the magnitude 24 (
) of the acceleration of the particle when the particle is not moving.
Answer:
t = 0.33h = 1200s
x = 18.33 km
Explanation:
If the origin of coordinates is at the second car, you can write the following equations for both cars:
car 1:
(1)
xo = 10 km
v1 = 55km/h
car 2:
(2)
v2 = 85km/h
For a specific value of time t the positions of both cars are equal, that is, x=x'. You equal equations (1) and (2) and solve for t:
![x=x'\\\\x_o+v_1t=v_2t\\\\(v_2-v_1)t=x_o\\\\t=\frac{x_o}{v_2-v_1}](https://tex.z-dn.net/?f=x%3Dx%27%5C%5C%5C%5Cx_o%2Bv_1t%3Dv_2t%5C%5C%5C%5C%28v_2-v_1%29t%3Dx_o%5C%5C%5C%5Ct%3D%5Cfrac%7Bx_o%7D%7Bv_2-v_1%7D)
![t=\frac{10km}{85km/h-55km/h}=0.33h*\frac{3600s}{1h}=1200s](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B10km%7D%7B85km%2Fh-55km%2Fh%7D%3D0.33h%2A%5Cfrac%7B3600s%7D%7B1h%7D%3D1200s)
The position in which both cars coincides is:
![x=(55km/h)(0.33h)=18.33km](https://tex.z-dn.net/?f=x%3D%2855km%2Fh%29%280.33h%29%3D18.33km)
Answer:0.27
Explanation:
Given
One worker Pushes with force ![F_1=430 N](https://tex.z-dn.net/?f=F_1%3D430%20N)
other Pulls it with a rope of rope ![F_2=360 N](https://tex.z-dn.net/?f=F_2%3D360%20N)
mass of crate ![m=290 kg](https://tex.z-dn.net/?f=m%3D290%20kg)
both forces are horizontal and crate slides with a constant speed
Both forces are in the same direction so Friction will oppose the forces and will be equal in magnitude of sum of two forces because crate is moving with constant speed i.e. net force is zero on it
![f_r=F_1+F_2](https://tex.z-dn.net/?f=f_r%3DF_1%2BF_2)
where
is the friction force
![f_r=430+360](https://tex.z-dn.net/?f=f_r%3D430%2B360%20)
![f_r=790 N](https://tex.z-dn.net/?f=f_r%3D790%20N)
![f_r=\mu N](https://tex.z-dn.net/?f=f_r%3D%5Cmu%20N)
where
is the coefficient of static friction
![N=mg](https://tex.z-dn.net/?f=N%3Dmg)
![790=\mu 29\cdot 9.8](https://tex.z-dn.net/?f=790%3D%5Cmu%2029%5Ccdot%209.8)
![\mu =0.27](https://tex.z-dn.net/?f=%5Cmu%20%3D0.27)
Answer:
![\Delta K=0.07969 J - 0.0849 J = -0.00521 J](https://tex.z-dn.net/?f=%5CDelta%20K%3D0.07969%20J%20-%200.0849%20J%20%3D%20-0.00521%20J)
Explanation:
According to the law of conservation of linear momentum, the total momentum of both pucks won't be changed regardless of their interaction if no external forces are acting on the system.
Being
and
the masses of pucks a and b respectively, the initial momentum of the system is
![M_1=m_av_a+m_bv_b](https://tex.z-dn.net/?f=M_1%3Dm_av_a%2Bm_bv_b)
Since b is initially at rest
![M_1=m_av_a](https://tex.z-dn.net/?f=M_1%3Dm_av_a)
After the collision and being
and
the respective velocities, the total momentum is
![M_2=m_av'_a+m_bv'_b](https://tex.z-dn.net/?f=M_2%3Dm_av%27_a%2Bm_bv%27_b)
Both momentums are equal, thus
Solving for ![v_a](https://tex.z-dn.net/?f=v_a)
![v_a=\frac{m_av'_a+m_bv'_b}{m_a}](https://tex.z-dn.net/?f=v_a%3D%5Cfrac%7Bm_av%27_a%2Bm_bv%27_b%7D%7Bm_a%7D)
![v_a=\frac{0.254Kg\times (-0.123 m/s)+0.367Kg (0.651m/s)}{0.254Kg}](https://tex.z-dn.net/?f=v_a%3D%5Cfrac%7B0.254Kg%5Ctimes%20%28-0.123%20m%2Fs%29%2B0.367Kg%20%280.651m%2Fs%29%7D%7B0.254Kg%7D)
The initial kinetic energy can be found as (provided puck b is at rest)
![K_1=\frac{1}{2}m_av_a^2](https://tex.z-dn.net/?f=K_1%3D%5Cfrac%7B1%7D%7B2%7Dm_av_a%5E2)
![K_1=\frac{1}{2}(0.254Kg) (0.8176m/s)^2=0.0849 J](https://tex.z-dn.net/?f=K_1%3D%5Cfrac%7B1%7D%7B2%7D%280.254Kg%29%20%280.8176m%2Fs%29%5E2%3D0.0849%20J)
The final kinetic energy is
![K_2=\frac{1}{2}m_av_a'^2+\frac{1}{2}m_bv_b'^2](https://tex.z-dn.net/?f=K_2%3D%5Cfrac%7B1%7D%7B2%7Dm_av_a%27%5E2%2B%5Cfrac%7B1%7D%7B2%7Dm_bv_b%27%5E2)
![K_2=\frac{1}{2}0.254Kg (-0.123m/s)^2+\frac{1}{2}0.367Kg (0.651m/s)^2=0.07969 J](https://tex.z-dn.net/?f=K_2%3D%5Cfrac%7B1%7D%7B2%7D0.254Kg%20%28-0.123m%2Fs%29%5E2%2B%5Cfrac%7B1%7D%7B2%7D0.367Kg%20%280.651m%2Fs%29%5E2%3D0.07969%20J)
The change of kinetic energy is
![\Delta K=0.07969 J - 0.0849 J = -0.00521 J](https://tex.z-dn.net/?f=%5CDelta%20K%3D0.07969%20J%20-%200.0849%20J%20%3D%20-0.00521%20J)
V=at and a=F/m
140/.070 = 2000m/s^2
2000*.020 = 40m/s
The ball’s velocity increased by 40m/s.