b) 4m/s/s
This is because you divide the speed you reach, by the time it takes to get to that speed:
12m/s ÷ 3s = 4m/s/s
The units come from what you divide, meters per second ÷ seconds this can be written as m/s/s or ms-²
Answer:
20 ms⁻¹
360 J
Explanation:
Kinetic energy is the energy possessed by a moving object solely due to its motion.
You can get the K.E. of an object using the equation,
K.E. = (1/2)mv² where all terms in usual meaning
So you get,
K.E. = 36000 = (1/2)×180×v²
v = 20 ms⁻¹
Also,
K.E. = (1/2)×80×3² = 360 J
Answer:
An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum. (option D)
Explanation:
Electronic fuel injection (EFI) system replaced carburetors back in the mid-1980s as the preferred method of supplying air and fuel to engines. The basic difference is that a carburetor uses intake vacuum and a pressure drop in the venturi, to siphon fuel from the carburetor fuel bowl into the engine. Whereas fuel injection system uses pressure to spray fuel directly into the engine.
However, under light load or at idle, a relatively high vacuum exists in the intake manifold. This means less fuel pressure is needed to spray a given volume of fuel through the injector. Under heavy load, engine vacuum drops to near zero.
Therefore, An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum.
The advantages of generating electricity using a hydroelectric power station rather than wind turbines is that it's not polluting anything since it's regular water. It also can be used over and over again.
The disadvantages of using a hydroelectric power station is that it can be very deadly and cause damage to towns if it overfills or falls apart releasing all the water. Since nothing lasts forever, eventually they will break apart and would require everyone to evacuate before doing so. Another disadvantage is that it disrupts migration of animals that live in the water such as fish.
It's better than wind turbines because wind turbines require a lot of wind to turn and on days without wind, very little energy can be produced.
