Answer:
option (D)
Explanation:
Here initial rotation speed is given, final rotation speed is given and asking for time.
If we use
A) θ=θ0+ω0t+(1/2)αt2
For this equation, we don't have any information about the value of angular displacement and angular acceleration, so it is not useful.
B) ω=ω0+αt
For this equation, we don't have any information about angular acceleration, so it is not useful.
C) ω2=ω02+2α(θ−θ0)
In this equation, time is not included, so it is not useful.
D) So, more information is needed.
Thus, option (D) is true.
Answer:
car crash,building destruction etc
Explanation:
is it helpful?
Answer: when you increase or decrease your speed.
Explanation:
Moving a skate at rest, you need to apply force in order to cause acceleration.
F = ma Where
F = force applied
m = mass of the skate
a = acceleration
The initial velocity u will be equal to zero and the skate will acceleration to a certain velocity.
as you skate down your neighborhood sidewalk, you will accelerate when you increase your speed. Because
Acceleration is the rate of change of velocity. That is,
Acceleration = change in velocity/ time.
And also, you will decelerate when you reduce the speed or velocity down your neighborhood sidewalk.