<h3><u>Answer;</u></h3>
- A moving electric charge creates a magnetic field at all points in the surrounding region.
- An electric current in a conductor creates a magnetic field at all points in the surrounding region.
- A permanent magnet creates a magnetic field at all points in the surrounding region.
<h3><u>Explanation;</u></h3>
- A magnetic field can be created by running electricity through a wire. All magnetic fields are created by moving charged particles. it is important to also note that charged particles create magnetic fields only when they are moving.
- The strength of the magnetic field generated or created is proportional to the amount of current flowing through the wire. Thus, increasing the current increases the strength of the magnetic field.
Answer:
single replacement
Explanation:
In the question it says one element replaces another element which means there is only one replacement.
Answer:
a) 
b) 

Explanation:
Searching the missed information we have:
E: is the energy emitted in the plutonium decay = 8.40x10⁻¹³ J
m(⁴He): is the mass of the helium nucleus = 6.68x10⁻²⁷ kg
m(²³⁵U): is the mass of the helium U-235 nucleus = 3.92x10⁻²⁵ kg
a) We can find the velocities of the two nuclei by conservation of linear momentum and kinetic energy:
Linear momentum:


Since the plutonium nucleus is originally at rest,
:
(1)
Kinetic Energy:

(2)
By entering equation (1) into (2) we have:
Solving the above equation for
we have:

And by entering that value into equation (1):
The minus sign means that the helium-4 nucleus is moving in the opposite direction to the uranium-235 nucleus.
b) Now, the kinetic energy of each nucleus is:
For He-4:

For U-235:

I hope it helps you!
Part a)
At t = 0 the position of the object is given as

At t = 2

so displacement of the object is given as

so average speed is given as

Part b)
instantaneous speed is given by


now at t= 0

at t = 1


at t = 2

Part c)
Average acceleration is given as



Part d)
Now for instantaneous acceleration
As we know that

at t = 0

at t = 1

now we have

At t = 2 we have



<em>so above is the instantaneous accelerations</em>