Answer:
Explanation:
Let the initial velocity of small block be v .
by applying conservation of momentum we can find velocity of common mass
25 v = 75 V , V is velocity of common mass after collision.
V = v / 3
For reaching the height we shall apply conservation of mechanical energy
1/2 m v² = mgh
1/2 x 75 x V² = 75 x g x 10
V² = 2g x 10
v² / 9 = 2 x 9.8 x 10
v² = 9 x 2 x 9.8 x 10
v = 42 m /s
small block must have velocity of 42 m /s .
Impulse by small block on large block
= change in momentum of large block
= 75 x V
= 75 x 42 / 3
= 1050 Ns.
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.
I do believe that the answer is D.
Hope this is right! Have a great day! :-)
Answer:
FALSE!!!
Explanation:
Business letters are formal and normally given to someone of higher importance.
Answer: The fundamental frequency of the slinky = 8Hz
An input frequency of 28 Hz will not create a standing wave
Explanation:
Let Fo = fundamental frequency
At third harmonic,
F = 3Fo
If F = 24Hz
24 = 3Fo
Fo = 24/3 = 8Hz
If an input frequency = 28 Hz at 3rd harmonic
Let find the fundamental frequency
28 = 3Fo
Fo = 28/3
Fo = 9.33333Hz
Since Fo isn't a whole number, it can't create a standing wave
