Answer:
The speed of the water shoot out of the hole is 20 m/s.
(d) is correct option.
Explanation:
Given that,
Height = 20 m
We need to calculate the velocity
Using formula Bernoulli equation

Where,
v₁= initial velocity
v₂=final velocity
h₁=total height
h₂=height of the hole from the base
Put the value into the formula




Hence, The speed of the water shoot out of the hole is 20 m/s.
Answer:
Force exerted, F = 1.5 N
Explanation:
It is given that, a boxer punches a sheet of paper in midair and brings it from rest up to a speed of 30 m/s in 0.060 s.
i.e. u = 0
v = 30 m/s
Time taken, t = 0.06 s
Mass of the paper, m = 0.003 kg
We need to find the force the boxer exert on it. The force can be calculated using second law of motion as :



F = 1.5 N
So, the force the boxer exert on the paper is 1.5 N. Hence, this is the required solution.
Answer:
Angular momentum = 0.7 kg.m²/s
Angular velocity = 583.3 rad/s
Explanation:
1. The torque τ is related to the angular momentum L by the relation
τ = ΔL/Δt
ΔL = τΔt
τ = 10 N. m
Δt = 70 ms = 70 × 10⁻³s
ΔL = (10 N. m) × (70 × 10⁻³s) = 700 × 10⁻³ kg.m²/s = 0.7 kg.m²/s
2. The rotational inertia I relates the angular momentum L to the angular velocity w
L = Iw
w = L/I
L = 0.7 kg.m²/s
I = 1.2 × 10⁻³ kg.m²
w = (0.7 kg.m²/s)/(1.2 × 10⁻³ kg.m²) = 583.3 rad/s
Power = Iω (constant) as they are connected together, since effort axle has large radius than resistance axle, so moment of inertia of effort axle is also more as compared to resistance axle, so angular speed of effort axle is less than the resistance axle. So answer is B. resistance axle will have more angular speed as its moment of inertia is less for the same power.