Answer:
Magnetic force, 
Explanation:
Given that,
A beryllium-9 ion has a positive charge that is double the charge of a proton, 
Speed of the ion in the magnetic field, 
Its velocity makes an angle of 61° with the direction of the magnetic field at the ion's location.
The magnitude of the field is 0.220 T.
We need to find the magnitude of the magnetic force on the ion. It is given by :

So, the magnitude of magnetic force on the ion is
.
Answer:
kinetic friction may be greater than 400 N or smaller than 400 N
Explanation:
As we know that maximum value of static friction on the rough surface is known as limiting friction and the formula of this limiting friction is known as

now when object is sliding on the rough surface then the friction force on that surface is known as kinetic friction and the formula of kinetic friction is known as

now we know that

so here value of limiting static friction force is always more than kinetic friction
also we know that
initially when body is at rest then static friction value will lie from 0 N to maximum limiting friction
and hence kinetic friction may be greater than static friction or if the static friction is maximum limiting friction then kinetic friction is smaller than static friction
so kinetic friction may be greater than 400 N or smaller than 400 N
<span>Mirage is due to (A). unequal heating of different parts of the atmosphere,
because that produces unequal density of different parts of the atmosphere,
which bends the light.
</span>
Answer:
0.5 m/s north
Explanation:
Take east to be +x, west to be -x, north to be +y, and south to be -y.
His displacement in the x direction is:
x = 20 m − 20 m = 0 m
His displacement in the y direction is:
y = 10 m
His total displacement is therefore 10 m north.
His velocity is equal to displacement divided by time.
v = 10 m north / 20 s
v = 0.5 m/s north
Answer:

Explanation:
- We have to make a hollow sphere of inner radius
and outer radius
.
Then the mass of the material required to make such a sphere would be calculated as:
Total volume of the spherical shell:

And the volume of the hollow space in the sphere:

Therefore the net volume of material required to make the sphere:


- Now let the density of the of the material be
.
<u>Then the mass of the material used is:</u>

