(a) The ball's height <em>y</em> at time <em>t</em> is given by
<em>y</em> = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve <em>y</em> = 0 for <em>t</em> :
0 = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
0 = <em>t</em> ((20 m/s) sin(40º) - 1/2 <em>g t</em> )
<em>t</em> = 0 or (20 m/s) sin(40º) - 1/2 <em>g t</em> = 0
The first time refers to where the ball is initially launched, so we omit that solution.
(20 m/s) sin(40º) = 1/2 <em>g t</em>
<em>t</em> = (40 m/s) sin(40º) / <em>g</em>
<em>t</em> ≈ 2.6 s
(b) At its maximum height, the ball has zero vertical velocity. In the vertical direction, the ball is in free fall and only subject to the downward acceleration <em>g</em>. So
0² - ((20 m/s) sin(40º))² = 2 (-<em>g</em>) <em>y</em>
where <em>y</em> in this equation refers to the maximum height of the ball. Solve for <em>y</em> :
<em>y</em> = ((20 m/s) sin(40º))² / (2<em>g</em>)
<em>y</em> ≈ 8.4 m
Answer:
boron has an atomic number of 5
but it has 6 neutron
Explanation:
there is no atom which has 5 neutrons and an atomic number of 5.
Answer:
A) car - 37500 kg*m/s, minivan - 13332 kg*m/s
B) 50832 kg*m/s
C) 18.83 m/s
Explanation:
Realize that sticky collisions are modeled by: m1v1+m2v2=(m1+m2) vf
conevert to m/s....car going 25 m/s, minivan going 11.11 m/s
A) p=mv
p(car)=(1500)(25)
p(car)=37500 kg*m/s
p(minivan)=(1200)(11.11)
p(minivan)=13332 kg*m/s
B) 37500+13332=50832 kg*m/s
C) 37500+13332=(1500+1200) vf
50832=2700(vf)
18.83 m/s = vf
Electric field strength near the surface of sphere is given by
![E = \frac{kQ}{r^2}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7BkQ%7D%7Br%5E2%7D)
Now we have
Q = 1 C
R = 5 cm
now electric field is given by
![E = \frac{9*10^9 * 1}{0.05^2}](https://tex.z-dn.net/?f=E%20%3D%20%5Cfrac%7B9%2A10%5E9%20%2A%201%7D%7B0.05%5E2%7D)
![E = 3.6 * 10^{12} N/C](https://tex.z-dn.net/?f=E%20%3D%203.6%20%2A%2010%5E%7B12%7D%20N%2FC)
Part B)
Since charge on the sphere is very large to electric field near its surface is too high. So this is reasonable result near it.
Part c)
As per our assumption the charge is uniformly distributed on the surface and there is no effect of surrounding charge or surrounding electric field.