placing a magnetically hard material in a strong magnetic field
Answer:
For the first one, its "attract"
Answer:
9.4 m/s
Explanation:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in kinetic energy of the system.
Therefore we can write:

where in this case:
W = -36,733 J is the work done by the parachute (negative because it is opposite to the motion)
is the initial kinetic energy of the car
is the final kinetic energy
Solving,

The final kinetic energy of the car can be written as

where
m = 661 kg is its mass
v is its final speed
Solving for v,

Answer:
potential energy increases.
Explanation:
The potential energy between the two charged particles is given by
U = k Q q / r
If they are very far apart then r tends to infinity and the potential energy is zero.
If they come closer then the potential energy between the two charged particles increases.
Thus, the potential energy increases.
Answer:
a. They will be tie
b. Win the wood cylinder
Explanation:
a.
The both cylinders will reach the bottom at the same time notice the relation in the equation in indepent of the length and both have the same radius and the same rotational inertia.


So both will be tie
b.

The acceleration of the wood cylinder is larger than the acceleration of the brass cylinder so the cylinder of wood will reach the bottom first

So the wood win the race