Answer:
Therefore it is save to carry a 62kg adult
Explanation:
From the question we are told that:
Mass 
Height of supporting Rock 
Length of Board
Mass of board 
Mass of adult
Generally the moment of balance about wedge part about is mathematically given by



where

therefore

if N=0 at fallen person

Therefore it is save to carry a 62kg adult
Polar molecules do have ionic bonds
Answer:
0.88752 kgm²
0.02236 Nm
Explanation:
m = Mass of ball = 1.2 kg
L = Length of rod = 0.86 m
= Angle = 90°
Rotational inertia is given by

The rotational inertia is 0.88752 kgm²
Torque is given by

The torque is 0.02236 Nm
Answer:
266.67Watts
Explanation:
Time = 2.5hr to seconds
3600s = 1hr
2.5hrs = 3600×2.5= 9000s
Force = 32N
Distance = 75km to m
1000m = 1km
75km = 1000×75 = 75000m
Power = workdone / time
Work = force × distance
Therefore work = 32N × 75000m
Work = 2400000Nm
Power = work ➗ time
Power = 2400000Nm ➗ 9000s
Power = 266.67Watts
Watts is the S. i unit of power
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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.