Answer:
The final velocity of the car is 36 m/s.
Explanation:
Given;
initial velocity of the car, u = 20 m/s
time of the car acceleration, t = 4 s
acceleration of the car, a = 4 m/s²
the final velocity of the car is calculated as;
v = u + at
where;
v is the final velocity of the car
v = 20 + (4 x 4)
v = 36 m/s
Therefore, the final velocity of the car is 36 m/s.
Answer:
Resistance = 400000 Ohms
Explanation:
Given the following data;
Voltage = 1200 V
Current = 3 mA = 3/1000 = 0.003 A
To find the resistance;
Voltage = current * resistance
Resistance = 1200/0.003
Resistance = 400000 Ohms
Answer:
a) W = 6.75 J and b) v = 3.87 m / s
Explanation:
a) In the problem the force is nonlinear and they ask us for work, so we must use it's definition
W = ∫ F. dx
Bold indicates vectors. In a spring the force is applied in the direction of movement, whereby the scalar product is reduced to the ordinary product
W = ∫ F dx
We replace and integrate
W = ∫ (-60 x - 18 x²) dx
W = -60 x²/2 -18 x³/3
Let's evaluate between the integration limits, lower W = 0 for x = -0.50 m, to the upper limit W = W for x = 0 m
W = -30 [0- (-0.50) 2] -6 [0 - (- 0.50) 3]
W = 7.5 - 0.75
W = 6.75 J
b) Work is equal to the variation of kinetic energy
W = ΔK
W = ΔK = ½ m v² -0
v =√ 2W/m
v = √(2 6.75/ 0.90)
v = 3.87 m / s
First, we will get the distance traveled before the driver applied the brakes.
distance = velocity * time
distance = 25*0.34 = 8.5 m
Now, we will calculated the distance that the car traveled after the driver applied the brakes. To do this, we will use the equation of motion:
<span>vf^2 = vi^2 + 2*a*d where:
</span>vf = zero, vi = 25 m/s and a = -7 m/s^2
Note: The negative sign is only to show deceleration
d = <span> 1/2*(625) /(7) = 44.6428 m
The total stopping distance =</span> 8.5 + 44.6428 = 53.1428 m
Frequency is measured in units of reciprocal time.
Period is measured in units of time.
Phase is a number without units that represents a fraction of a wave.
None of these is measured in meters, so none of them can be the answer.
It must be either amplitude or wavelength.
Amplitude is a quantity that's measured at one or two points in the same wave.
The question is talking about points on consecutive waves.
<em>Wavelength is</em> the only choice left. That must be it.
