Answer:
A.
Explanation:
The SUV accelerates uniformly. In this case, speed () is directly proportional to time (). That is:
(1)
Where is the proportionality constant.
Then, we eliminate this constant by creating the following relationship:
(2)
If we know that , and , then the time interval for the SUV to accelerate from rest to a speed is:
Hence, correct answer is A.
Answer:
20 Ω
Explanation:
Voltage, current, and resistance are related by Ohm's law:
V = IR
40 V = (4 A) R
R = 10 Ω
The total resistance of the circuit is 10 Ω.
Resistors in parallel have a total resistance of:
1/R = 1/R₁ + 1/R₂
1 / (10 Ω) = 1 / (20 Ω) + 1/R₂
R₂ = 20 Ω
Answer:
Since velocity is a vector quantity there is no net displacement and the average velocity is zero
(A) is correct
Answer:
Choices A, B, and C are correct.
Explanation:
Let us look at each of the choices one by one:
A. It is a vector
Yes. Velocity is a vector, or it's a speed with direction.
B. It is the change in displacement divided by the change in time.
Yes. The velocity can be written as
where is the displacement—a vector quantity.
C. It can be measured in meters per second.
Yes. The units of velocity are m/s, but also with a unit vector indicating the direction.
D. It is the slope of the acceleration vs. time graph.
Nope. The velocity is the slope of displacement vs. time graph.
Hence, only choices A, B, and C are correct.