False! The ability to cause change is energy, not matter. <span />
<h2>Answer: 12.24m/s</h2>
According to <u>kinematics</u> this situation is described as a uniformly accelerated rectilinear motion. This means the acceleration while the car is in motion is constant.
Now, among the equations related to this type of motion we have the following that relates the velocity with the acceleration and the distance traveled:
(1)
Where:
is the Final Velocity of the car. We are told "the car comes to a stop after travelling", this means it is 0.
is the Initial Velocity, the value we want to find
is the constant acceleration of the car (the negative sign means the car is decelerating)
is the distance traveled by the car
Now, let's substitute the known values in equation (1) and find :
(2)
(3)
Multiplying by -1 on both sides of the equation:
(4)
(5)
Finally:
>>>This is the Initial velocity of the car
Answer:
(a) The power wasted for 0.289 cm wire diameter is 15.93 W
(b) The power wasted for 0.417 cm wire diameter is 7.61 W
Explanation:
Given;
diameter of the wire, d = 0.289 cm = 0.00289 m
voltage of the wire, V = 120 V
Power drawn, P = 1850 W
The resistivity of the wire, ρ = 1.68 x 10⁻⁸ Ω⋅m
Area of the wire;
A = πd²/4
A = (π x 0.00289²) / 4
A = 6.561 x 10⁻⁶ m²
(a) At 26 m of this wire, the resistance of the is
R = ρL / A
R = (1.68 x 10⁻⁸ x 26) / 6.561 x 10⁻⁶
R = 0.067 Ω
Current in the wire is calculated as;
P = IV
I = P / V
I = 1850 / 120
I = 15.417 A
Power wasted = I²R
Power wasted = (15.417²)(0.067)
Power wasted = 15.93 W
(b) when a diameter of 0.417 cm is used instead;
d = 0.417 cm = 0.00417 m
A = πd²/4
A = (π x 0.00417²) / 4
A = 1.366 x 10⁻⁵ m²
Resistance of the wire at 26 m length of wire and 1.366 x 10⁻⁵ m² area;
R = ρL / A
R = (1.68 x 10⁻⁸ x 26) / 1.366 x 10⁻⁵
R = 0.032 Ω
Power wasted = I²R
Power wasted = (15.417²)(0.032)
Power wasted = 7.61 W
Answer:
<h3>The answer is 500 km </h3>
Explanation:
The distance covered by an object given it's velocity and time taken can be found by using the formula
<h3>distance = average velocity × time</h3>
From the question
average speed = 250 km/h
time = 2 hrs
We have
distance = 250 × 2
We have the final answer as
<h3>500 km</h3>
Hope this helps you
