Answer:
d. 37 °C
Explanation:
= mass of lump of metal = 250 g
= specific heat of lump of metal = 0.25 cal/g°C
= Initial temperature of lump of metal = 70 °C
= mass of water = 75 g
= specific heat of water = 1 cal/g°C
= Initial temperature of water = 20 °C
= mass of calorimeter = 500 g
= specific heat of calorimeter = 0.10 cal/g°C
= Initial temperature of calorimeter = 20 °C
= Final equilibrium temperature
Using conservation of heat
Heat lost by lump of metal = heat gained by water + heat gained by calorimeter

Answer:

Explanation:
given,
radius of loop = 12.1 m
to find the minimum speed transverse by the rider to not to fall out upside down
centripetal force = 
gravitational force = m g
computing both the equation]





Answer:
Kinetic energy is the amount of energy a object has while it's in motion, and thermal energy is heat energy. In this case when the heat rises in substances for example a solid it will transform into a liquid causing the molecules to move faster which is a increase of kinetic energy.
Explanation:
Answer:
0.214 m
Explanation:
In order for the bag to levitate and not fall down, the electrostatic force between the bag and the balloon must balance the weight of the bag.
Therefore, we can write:

where
k is the Coulomb constant
is the charge on the balloon
is the charge on the bag
r is the separation betwen the bag and the balloon
is the mass of the bag
is the acceleration due to gravity
Solving for r, we find the distance at which the bag must be held:

<h2>Snow starts to move down the mountain </h2>
The energy which is due to position is potential energy. So when the snow is lying on the mountain. It possess potential energy but when suddenly, it starts to move down the mountain, the potential energy is converted into the kinetic energy. Yet some force is exerting on the snow to stop the smooth flow of snow through mountains.
This example of frictional force may be due to presence of rough surface or stones. Generally, there are four types of friction as static, rolling, sliding and fluid friction. Though in this case when snow is lying it possess static friction, when flows then it possesses sliding and fluid friction both.