Answer:
Option C
Explanation:
Scalar quantities are described by its magnitude only. They do not need to be described by the direction. So, 20 miles per hour is the scalar quantity.
Answer:
192000 J or 192 kJ
Explanation:
Work done = Force × distance moved along the direction of force.
From the question,
W = F×d............... Equation 1
Where W = work done by the car, F = Force of the car, d = distance move by the car along the direction of the force.
We can calculate for d using the equation of motion
d = (v+u)t/2..................... Equation 2
Where v = Final velocity of the car, u = Initial velocity of the car, t = time.
Given: u = 12 m/s, v = 0 m/s(skids to a stop), t = 4.0 s
Substitute into equation 2
d = (12+0)4/2
d = 24 m.
Also given: F = 8000 N
Substitute into equation 1
W = 8000×24
W = 192000 J
W = 192 kJ.
Answer:
Yes it is true
As the Hubble's law states that the observation in physical cosmology that galaxies are moving away from the Earth at speeds proportional to their distance.
Explanation:
