(1 cal/g °C) x (4000 g) x (45 - 25)°C = 80000 cal = 80 kcal. So the answer is 80 kcal .
Answer:
The Hydrostatic force is 
The location of pressure center is
Explanation:
From the question we are told that
The height of the gate is 
The weight of the gate is 
The height of the water is 
The density of water is 
Note used
for height of water and height of gate immersed by water since both have the same value
The area of the gate immersed in water is mathematically represented as

substituting values


The hydrostatic force is mathematically represented as

Where


So


The center of pressure is mathematically represented as

Where
is the moment of inertia of the gate which mathematically represented as

The
is the height of gate immersed in water
Thus


Answer: True
Explanation:
A photo detector that can respond to the entire rang of visible light can be design, it is true.
Photo detector is a device in an optical receiver which receives optical signals and convert it to electric signal. It is the key device position in front of the optical receiver.
Using g = 9.8 m/s2, the statement that best describes the roller coaster car when it is at the top of the loop-de-loop is that The car has both potential and kinetic energy, and it is moving at 24.6 m/s.
The correct answer is <span>B) The car has both potential and kinetic energy, and it is moving at 24.6 m/s.</span>
Answer:
4.5kgm/s
Explanation:
Change in momentum is expressed as
Change in momentum = m(v-u)
M is the mass
V is the final velocity
u is the initial velocity
Given
m=0.45kg
v = 30m/s
u = 20m/s
Substitute
Change in momentum = 0.45(30-20)
Change in momentum = 0.45×10
Change in momentum = 4.5kgm/s