Answer:
6
Explanation:
The magnetic field inside a solenoid is given by the following formula:

where,
B = Magnetic Field Inside Solenoid
μ₀ = permittivity of free space
n = No. of turns per unit length
I = Current Passing through Solenoid
For Solenoid 1:

For Solenoid 2:
n₂ = 6n₁
Therefore,

Diving equation 1 and equation 2:

Hence, the correct option is:
<u>6</u>
Answer:
51.96 m/s^-1
Explanation:
a) see the attachment
b) As we know the velocity of the projectile has two component, horizontal velocity v_ox. and vertical velocity v_oy as shown in the figure. At the highest point of the trajectory, the projectile has only horizontal velocity and vertical velocity is zero. Therefore at the highest point of the trajectory, the velocity of the projectile will be
v_ox=v_o*cosФ
=60*cos (30)
= 51.96 m/s^-1
1 atm corresponds to 760 mmHg, so we can set up a simple proportion to find how many atmospheres correspond to 570 mmHg:

and from this, we find