Answer:
The answer will be 936 N.
Explanation:
Given that
m = 80 kg
Acceleration of the elevator , a= 1.7 m/s² ( upward)
The gravity force on the mass = m g
The reading on the scale = F N
Now by applying the Newton's second law
F - m g = ma
F= m g + m a
F= m ( g +a )
F= 80 ( 10 + 1.7 ) N ( take g= 10 m/s²)
F=80 x 11.7 N
F= 936 N
Therefore the reading on the scale will be 936 N.
The answer will be 936 N.
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.
To solve this problem we will use the concepts related to Magnification. Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification".
The overall magnification of microscope is
Where
N = Near point
l = distance between the object lens and eye lens
= Focal length
= Focal of eyepiece
Given that the minimum distance at which the eye is able to focus is about 25cm we have that N = 25cm
Replacing,
Therefore the correct answer is C.
Wavelength of the water wave is 8 m
Explanation:
- Wavelength measures the distance between two successive crests or troughs of the wave. It is given by the following equation
λ = v/f, where f is the frequency, v is the velocity of the wave
Here, v = 20 m/s and f = 2.5 Hz
⇒ λ = 20/2.5
= 8 m
Answer:
power =( 890 N x 12 m ) / 22 s=
= 485 Watts
Explanation:
