Answer:

Explanation:
It is given that,
Mass of the car, m = 763 kg
Speed of the car, v = 26 m/s
Mass of the iron, m' = 15 kg
Specific heat of iron, c = 450 J/kg
When the car is in motion, it will possess kinetic energy. It is given by :


K = 257894 J
Since, energy is absorbed by the brakes. The kinetic energy of the car is absorbed by the brakes. So,

is the increase in temperature of the brakes



So, the increase in temperature of the brakes is 38.20 degrees Celsius. Hence, this is the required solution.
Answer:
the bottle would stay in its squashed shape, and it will only regain its shape if u remove the cork
Explanation:
because theres not enough air inside to let the bottle to go back its normal form. Its like when u let the air out of a balloon, theres no air inside to let it stay in its 'big or expanded' form.
Answer:
The compression is
.
Explanation:
A Hooke's law spring compressed has a potential energy

where k is the spring constant and
the distance to the equilibrium position.
A mass m moving at speed v has a kinetic energy
.
So, in the first part of the problem, the spring is compressed a distance d, and then launch the mass at velocity
. Knowing that the energy is constant.

If we want to double the kinetic energy, then, the knew kinetic energy for a obtained by compressing the spring a distance D, implies:

But, in the left side we can use the previous equation to obtain:





And this is the compression we are looking for
By Kirchoff's law in left side loop

similarly kirchoff's law in right side loop

also by junction law we know that

now by plug in all values we have




So by solving above equations we have



It is b. sodium because it is in group 1