The answer is has no moons. Mars has two moons
That's 105 km that he flew, or 65.2 miles ! I'm absolutely positive
that the crow must have landed and gotten some rest when you
weren't looking. But that had no effect on his displacement when
he got where he was going, so we can continue to solve the problem:
The displacement is the distance and direction from the place
where the crow took off to the place where he landed.
-- It's distance is the hypotenuse of the right triangle whose legs
are 60 km and 45 km.
D² = (60 km)² + (45 km)²
= 3,600 km² + 2,025 km² = 5,625 km²
D = √(5625 km²) = 75 km .
-- It's direction is the angle whose tangent is (45 S / 60 W).
tan⁻¹ (45/60) = tan⁻¹ (0.75) = 36.9° south of west
= 53.1° west of south.
= not exactly southwest but close.
Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
