An object is hanging from a rope. When it is held in air the tension in the rope is 8.86 N, and when it is submerged in water th
1 answer:
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Answer:
t = 6 minutes
Explanation:
Given that,
Force,
Initial speed of the train, u = 0
Final speed of the train, v = 80 km/h = 22.22 m/s
The mass of the train,
We need to find the time taken by the train to come to rest. We know that,
F = ma
or
t = 6 minutes (approx)
So, the required time is equal to 6 minutes.
Answer:
(B) 15 N.m
Explanation:
The deceleration of the wheel is first found by using the following formula:
where,
α = angular acceleration = ?
ωf = final angular speed = 0 rad/s
ωi = initial angular speed = 12 rad/s
t = time = 0.4 s
Therefore,
here, the negative sign shows deceleration.
Now, we find the torque responsible for this deceleration:
where,
τ = torque = ?
I = rotational inertia = 0.5 kg.m²
Therefore,
τ = 15 N.m
Therefore, the correct answer is:
<u>(B) 15 N.m</u>