Answer:
t = 4.1 seconds
Explanation:
It is given that,
Width of road which is to be crossed by a man is 8.25 m, it means it is distance to be covered.
Speed of man is 2.01 m/s
We need to find the time taken by the man to cross the road. It is a concept of speed. Speed of a person is given by total distance covered divided by time taken. So,
t is time taken
So, the time taken by the man to cross the road is 4.1 seconds.
Answer:
(a) 3.807 s
(b) 145.581 m
Explanation:
Let Δt = t2 - t1 be the time it takes from the moment when the motorcycle starts to accelerate until it catches up with the car. We know that before the acceleration, both vehicles are travelling at a constant speed. So they would maintain a distance of 58 m prior to the acceleration.
The distance traveled by car after Δt (seconds) at speed is
The distance traveled by the motorcycle after Δt (seconds) at speed and acceleration of a = 8 m/s2 is
We know that the motorcycle catches up to the car after Δt, so it must have covered the distance that the car travels, plus their initial distance:
(b)
Answer:
1.43 s
Explanation:
The time it takes for the container to reach the ground is determined only by the vertical motion of the container, which is a free-fall motion, so a uniformly accelerated motion with a constant acceleration of g=9.8 m/s^2 towards the ground.
The vertical distance covered by an object in free fall is given by
where
u = 0 is the initial vertical speed
t is the time
a= g = 9.8 m/s^2 is the acceleration
since u=0, it can be rewritten as
And substituting S=10.0 m, we can solve for t, to find the duration of the fall:
Answer: a) 1 b) 61 W c) 61 W
Explanation:
a) The Power Factor (also known as cos φ), is defined by the difference in phase between current and voltage, in a RLC series circuit, and is expressed as follows:
cos φ = R / Z = R /
In resonance, XL =XC, so the circuit behaves like it were purely resistive, so Z=R.
Replacing in the expression for power factor, we have:
cos φ = R/Z = R/R = 1
This means that in resonance, current and voltage are in phase each other.
b) The average power delivered by the source, in resonance, is simply the power dissipated at the resistance R, as follows:
Pavg = V² rms / R = V₀² / √2 / R = 61 W
c) If the circuit remains in resonance, the average power , which does not depends on frequency provided this condition remains, keeps the same, i.e. , 61 W.