Answer:
Time = 11.60 seconds.
Explanation:
Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.
Mathematically, speed is given by the equation;
Given the following data;
Speed = 0.711m/s
Distance = 8.25m
To find the time;
Making time the subject of formula, we have;
Substituting into the equation, we have;
Time = 11.60 secs.
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.
There's so much going on here, in a short period of time.
<u>Before the kick</u>, as the foot swings toward the ball . . .
-- The net force on the ball is zero. That's why it just lays there and
does not accelerate in any direction.
-- The net force on the foot is 500N, originating in the leg, causing it to
accelerate toward the ball.
<u>During the kick</u> ... the 0.1 second or so that the foot is in contact with the ball ...
-- The net force on the ball is 500N. That's what makes it accelerate from
just laying there to taking off on a high arc.
-- The net force on the foot is zero ... 500N from the leg, pointing forward,
and 500N as the reaction force from the ball, pointing backward.
That's how the leg's speed remains constant ... creating a dent in the ball
until the ball accelerates to match the speed of the foot, and then drawing
out of the dent, as the ball accelerates to exceed the speed of the foot and
draw away from it.
The answer should be 11,460 because the first half-life leaves 50 percent left and the next half-life would leave 25 percent which dates the bones at 11,460 years old.
