Langerhans cells exist on the surface of the skin. They help to protect you by keeping dangerous microbes from entering your body. Langerhans cells do this in two very different ways: by protecting your skin from infection and also by stimulating allergic reactions.
The first law of thermodynamics states that energy cannot be created nor destroyed. It can be transformed from one form of energy to another, but the energy in an isolated system remains constant.
The answer then would be letter B. False.
Answer:
Work done by a tug boat, W = 1.735 x 10⁸ J
Explanation:
Given,
The of each tugboat, F = 1.5 x 10⁶ N
The angle of each tugboat forms with the resultant force, θ = 19°
The displacement of the supertanker, s = 710 m
The individual tugboat will be responsible for the displacement, d = 710/2
= 355 m
The displacement component in each tugboat direction = 355 · sin θ meter
Therefore, the work done by each tugboat is
W = F x S joules
Substituting the values in the above equation
W = 1.5 x 10⁶ x 355 · sin θ
= 1.735 x 10⁸ J
Hence, the work done by each tugboat is, W = 1.735 x 10⁸ J
Answer:
Explanation: A bar of an unknown metal has a length of 0.975 m at 45°C and a length of 0.972 m at. 23°C.
Answer:
A,B,D,E are wrong
(A) Heat exchangers are devices where two moving fluid streams are mixed together (B) Heat exchangers are devices where two moving fluid streams exchange mass (D) Heat exchangers are devices where two moving fluid streams exchange mechanical work without mixing together (E) There is no heat transfer between the two fluids of an insulated heat exchanger
Explanation:
A heat exchanger can be regarded as a system that bring about transfer heat between two or more than two fluids. It can function in cooling process and heating processes, the fluids involves in this process can have a solid wall to separate them so as to prevent mixing, direct contact could also be utilized. The mechanism is making hot gas jets which could fire upward over a glowing water that is passing through pipes, as water moves along the pipe, heat energy is been absorbed and there is heating up i.e heat is transferred. One is cooked the other is heated up. It is very essential to insulate the whole steam system along with heat exchangers so that energy could be saved and the temperature of the surface would be at safe-to-touch range and also steam quality could be maintained. The types of heat exchanger we have are;
✓Shell and tube heat exchangers.
✓Condensers, evaporators, and boilers
✓Double pipe heat exchangers.
✓Plate heat exchangers.
It should be noted Heat exchangers are devices where two moving fluid streams exchange heat (thermal energy) without mixing together
