Answer:
52 rad
Explanation:
Using
Ф = ω't +1/2αt²................... Equation 1
Where Ф = angular displacement of the object, t = time, ω' = initial angular velocity, α = angular acceleration.
Since the object states from rest, ω' = 0 rad/s.
Therefore,
Ф = 1/2αt²................ Equation 2
make α the subject of the equation
α = 2Ф/t².................. Equation 3
Given: Ф = 13 rad, t = 2.5 s
Substitute into equation 3
α = 2(13)/2.5²
α = 26/2.5
α = 4.16 rad/s².
using equation 2,
Ф = 1/2αt²
Given: t = 5 s, α = 4.16 rad/s²
Substitute into equation 2
Ф = 1/2(4.16)(5²)
Ф = 52 rad.
formula for gravitational P.E =mgh
Solution:-mass=3kg height=5metre and gravity=9.8 or 10m/sec² so P.E=mgh , 3×9.8×5=147kgm²/sec²
Magnetic fields
Explanation:
The presence of magnetic fields best explains why a magnet can act a distance on other magnets or on objects containing certain metals.
- Magnetic fields are lines of forces around a bar magnet.
- These lines of forces attracts and repels other magnetic bodies and metallic bodies round it.
- Magnetic lines of forces originates at the north pole and enters in the south pole.
- Areas around a magnetic body are bounded by force fields.
- A magnet has permanent magnetic fields round it.
learn more:
Electromagnet brainly.com/question/2191993
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