Answer:
<em>0.45 mm</em>
Explanation:
The complete question is
a certain fuse "blows" if the current in it exceeds 1.0 A, at which instant the fuse melts with a current density of 620 A/ cm^2. What is the diameter of the wire in the fuse?
A) 0.45 mm
B) 0.63 mm
C.) 0.68 mm
D) 0.91 mm
Current in the fuse is 1.0 A
Current density of the fuse when it melts is 620 A/cm^2
Area of the wire in the fuse = I/ρ
Where I is the current through the fuse
ρ is the current density of the fuse
Area = 1/620 = 1.613 x 10^-3 cm^2
We know that 10000 cm^2 = 1 m^2, therefore,
1.613 x 10^-3 cm^2 = 1.613 x 10^-7 m^2
Recall that this area of this wire is gotten as
A = 
where d is the diameter of the wire
1.613 x 10^-7 = 
6.448 x 10^-7 = 3.142 x 
=
d = 4.5 x 10^-4 m = <em>0.45 mm</em>
Answer:
2.8 m 7.4 m/s
Explanation:
write all the values then use the equations of motion to find the distance and speed. please see attached photo
Answer:
The cannons total flight time is 2.23seconds
Explanation:
A ball fired diagonally is fired at an angle of 45° to the horizontal. The motion of the fired ball is a projectile motion. A projectile is a motion in which an object fired into space with an initial velocity U is allowed to fall freely under the influence of gravitational force.
To total time of flight T of the cannon ball can be expressed as;
T = 2Usin(theta)/g where;
U is the initial velocity or speed of the ball = 31m/s
theta is the angle that the ball make with the horizontal = 45°
g is the acceleration due to gravity = 9.81m/s²
Substituting the given datas into the formula we have;
T = 31sin45°/9.81
T = 31×0.7071/9.81
T = 21.92/9.81
T = 2.23seconds
The radius of the wire loop is
, so the area enclosed by the loop is
Initially, the magnetic field intensity is B=5.0 mT=0.005 T, so the magnetic flux throug the wire loop is
Answer:
The minimum speed = 
Explanation:
The minimum speed that the rocket must have for it to escape into space is called its escape velocity. If the speed is not attained, the gravitational pull of the planet would pull down the rocket back to its surface. Thus the launch would not be successful.
The minimum speed can be determined by;
Escape velocity =
where: G is the universal gravitational constant, M is the mass of the planet X, and R is its radius.
If the appropriate values of the variables are substituted into the expression, the value of the minimum speed required can be determined.
