Answer:
Radius of cross section, r = 0.24 m
Explanation:
It is given that,
Number of turns, N = 180
Change in magnetic field, 
Current, I = 6 A
Resistance of the solenoid, R = 17 ohms
We need to find the radius of the solenoid (r). We know that emf is given by :


Since, E = IR




or

Area of circular cross section is, 


r = 0.24 m
So, the radius of a tightly wound solenoid of circular cross-section is 0.24 meters. Hence, this is the required solution.
Answer:
817.5 Pa
Explanation:
From Bernoulli's equation, considering thst there is no height difference then
P1+½d(v1)²=P2+½d(v2)²
P1-P2=½d(v2²-v1²)
∆P=½d(v2²-v1²)
Where P represent pressure, d is density and v is velocity. Subscripts 1 and 2 represent inside and outside. ∆P is tge change in pressure
Given the speed at roof top as 128 km/h, we convert it to m/s as follows
128*1000/3600=35.555555555555=35.56 m/s
Velocity at the bottom of roof is 0 m/s
Density is given as 1.293 kg/m³
∆P=½*1.293*(35.56²-0)=817.5 Pa
<span>stuntman's vertical velocity is
vy= 6 sin 15=1.55m/s.
Height that he goes up is,
vertical kinetic energy = mgh
1/2 v² = gh, h=v²/(2g)=0.12 m.
time wanted to go up= vy/9.8=0.16s, Time to fall through a height
0.12+2.9=3.02m is
t=sqrt(3.02*2/9.8)=0.78 s
Total time needed to go up and down is 0.78+0.16=0.94 s.
to calculate the horizontal range,
Horizontal velocity = 6 cos 15=5.8 m/s.
Distance which he can cover is
5.8*0.94=5.44 m.
If the distance between the two building is less than 5.44 m then he will be safe and he can jump that distance.</span>