Answer:
<h3>The answer is option B</h3>
Explanation:
The frequency of a wave can be found by using the formula

where
c is the velocity
From the question
wavelength = 0.39 m
c = 86 m/s
We have

We have the final answer as
<h3>200 Hz</h3>
Hope this helps you
Answer:
a) 2cm³
b) 100 g/cm³
Explanation:
a- 9-7= 2cm³
b- 200 divided by 2= 100 g/cm³
Hope this helps... correct me if i'm wrong
Answer:
2. west
Explanation:
Given an electron is moving vertically upward from ground.
Now Fleming right hand rule state that: make L shape with thumb and index finger then point middle finger perpendicular to index and thumb.Then index finger points in the direction of moving charge , middle finger points in the direction of the magnetic field and thumb points in the direction of the magnetic force.
According to Fleming right hand rule the direction of the magnetic that acts on the electron is west.
Answer:

Explanation:
Average speed is given by
where
is total distance and
is time.
Plugging in given values, we get:
.
Answer:
Explanation:
Given that
F=ax^3/2. a is a constant
The force does a work of
W=2.01KJ from x=0 to x=15.2m
We need to find a
Work is give as,
W=∫F.ds
But this is in x direction only then,
W=∫Fdx. from x=0 to x=15.2m
W=∫ax^3/2dx from x=0 to x=15.2m
W=ax^(3/2+1)/(3/2+1).
W=ax^(5/2)/5/2
W=ax^(2/5)/2.5 from x=0 to x=15.2m
Cross multiply
2.5W=ax^2.5. from x=0 to x=15.2m
2.5W= a (15.2^2.5-0)
W=2.01KJ=2010J
2.5×2010=a×900.76
Therefore,
a=5.56