To solve this problem it is necessary to apply the concepts related to the conservation of energy and heat transferred in a body.
By definition we know that the heat lost must be equal to the heat gained, ie
Where,
Q = Heat exchange
The heat exchange is defined as
Where,
Specific heat
m = mass
Change in Temperature
Therefore replacing we have that
Replacing with our values we have that
Therefore the highest possible temperature of the spoon when you finally take it out of the cup is 75.24°C
Work formula:
F = 50N, d = 1.0 m
When you lift something straight up, the angle of the force is 90º
cos(90º) is 0, so there's no work done when you lift the microwave off the ground
F = 50N, d = 1.0 m
When you push the microwave, the angle is 0º and cos(0º) is 1. So there is work done here:
total work = 50 joules
To calculate the initial velocity of the bike, we use the following equation
.
or
Here, u is initial velocity, v is final velocity, t is the time and d is the distance covered by bike.
Given, ,
and
.
Substituting these values in above equation, we get
.
Thus, the initial velocity of the bike is 1.2 m/s.