Answer:
Explanation:
m = Mass of automobile = 1100 kg
v = Velocity of car = 120 km/h = 
h = Height of hill = 80 m
g = Acceleration due to gravity = 
Change in kinetic energy
Change in kinetic energy is
Change in potential energy is given by
The change in potential energy is .
Answer:
E = 2940 J
Explanation:
It is given that,
Mass, m = 12 kg
Position at which the object is placed, h = 25 m
We need to find the potential energy of the mass. It is given by the formula as follows :
E = mgh
g is acceleration due to gravity
So, the potential energy of the mass is 2940 J.
Answer:
True
Explanation:
in a lightning for example we can see energy flowing in the environment.
The most easy way of seeing this is with the evaporation of the water in the sea because of the energy coming from the sun, the energy is used to change the state of the matter in water, changing it from liquid to gas. The energy is conservated and used for the environment.
Answer:
Answer in explanation
Explanation:
Initial setting time is the time when the cement starts losing plasticity or begins hardening after addition of water to it.
Final setting time is the time when the cement has completly lost it's plasticity and has set and became hard after addition of water.
The test carried out is vicat's penetration test
The initial setting time can be defined as “time taken by paste to stiffen to such an extent that the Vicatt’s needle is not permitted to move down through the paste through 25 mm.”.
The final setting time can be defined as “ it is the time after which the paste becomes so hard that Vicatt’s 5mm needle doesn’t sinks visibly and leave no impression”.
The importance and use of setting time test of cement paste samples
The importance of setting time test is that it plays a very vital role in the fresh and used(hardened) state of concrete.
It plays a very important role in mixing, transportation, shrinkage, compacting, finishing and removal of formwork
The importance of compressive strength of mortar cubes is that it is the compressive strength that tells us about the performance characteristics of the binder of the concrete which is the cement in this case. The performance characteristics deals with the overall quality of the finished product. Hence, a cement or mortar with good compressive strength is good to ensure the delivery of quality work in the final concrete.
It is important to note that there are applicable standards in form of numbers for compressive strength of a cement or mortar
Answer:
The rate of energy absorbed per unit time is 3500W.
Explanation:
From the question, we were given the following parameters;
Plane, opaque, gray, diffuse surface
â = 0.7
Surface area, A = 0.5m²
Incoming radiant energy, G = 10000w/m²
T = 500°C
Rate of energy absorbed is âAG;
âAG = 0.7 × 0.5 × 10000
âAG = 3500W.
The energy absorbed is measured in watts and denoted by the symbol W.
