Instantaneous velocity, on the other hand, describes the motion of a body at one particular moment in time. Acceleration is a vector which shows the direction and magnitude of changes in velocity. Its standard units are meters per second per second, or meters per second squared. (this is for number 3)
To solve this problem it is necessary to apply the definition of severity of Newtonian laws in which it is specified that gravity is defined by

Where
G= Gravitational Constant
M = Mass of Earth
R= Radius from center of the planet
According to the information we need to find the gravity 350km more than the radius of Earth, then



Therefore the gravitational acceleration at 350km is 
Answer:
A solenoid is a device comprised of a coil of wire, the housing and a moveable plunger (armature). When an electrical current is introduced, a magnetic field forms around the coil which draws the plunger in. More simply, a solenoid converts electrical energy into mechanical work.
Explanation:
The coil is made of many turns of tightly wound copper wire. When an electrical current flows through this wire, a strong magnetic field/flux is created.
The housing, usually made of iron or steel, surrounds the coil concentrating the magnetic field generated by the coil.
The plunger is attracted to the stop through the concentration of the magnetic field providing the mechanical force to do work.
Answer:
122.84 J
Explanation:
Since plate is square, area, A is given by 
The distance between plates, d, is given in the question as 2mm=0.002m
Charge on plate, Q, as given in the question is 240 
Assuming mica dielectric constant, k of 7
Capacitance, C is given by
C=
Stored energy, E is given by
E=
Therefore, the stored energy is 122.84 J