Answer:
(a) the time needs for her to cross the river is 2736.8 s.
(b) the distance takes to reach the other side of the river is 2490.5 m.
Explanation:
given information:
woman's speed, v₁ = 1.9 m/s
the wide of river, s = 5.2 km = 5200 m
river's current, v₂ = 0.91 m/s
(a) How much time does it take her to cross the river?
s = v t
s = the displacement (m)
v = speed (m/s)
t = time (s)
s = v t
t = s/v
= 5200/1.9
= 2736.8 s
(b) How far downstream will the river carry her by the time she reaches the other side of the river?
s = v t
= (0.91) (2736.8)
= 2490.5 m
Answer:
a. 5.23 m/s² b. 44.23 N
Explanation:
a. What is the centripetal acceleration of the hammer?
The centripetal acceleration a = rω² where r = radius of circle and ω = angular speed.
Now r = length of chain = 1.4 m and ω = 0.595 rev/s = 0.595 × 2π/s = 3.74 rad/s.
So a = rω²
= 1.4 m × (3.74 rad/s)²
= 5.23 m/s²
b. What is the tension in the chain?
The tension in the chain, T = ma where m = mass of hammer = 8.45 kg and a = centripetal acceleration of hammer = 5.23 m/s². This tension is the centripetal force on the hammer.
So, T = 8.45 kg × 5.23 m/s²
= 44.23 N
The density of silver is ρ = 10500 kg/m³ approximately.
Given:
m = 1.70 kg, the mass of silver
t = 3.0 x 10⁻⁷ m, the thickness of the sheet
Let A be the area.
Then, by definition,
m = (t*A)*ρ
Therefore
A = m/(t*ρ)
= (1.7 kg)/ [(3.0 x 10⁻⁷ m)*(10500 kg/m³)]
= 539.7 m²
Answer: 539.7 m²
The electrostatic force is directly proportional to the product of the charges, by Coulomb's law.
F α Qq
If the charges are now half the initial charges:
<span>F α (1/2)Q *(1/2)q
</span>
F α (1/4)Q<span>q
The new force when the charges are each halved is (1/4) the first initial force experienced at full charge.</span>
A mechanical wave<span> requires an initial </span>energy<span> input. Once this initial </span>energy<span> is added, the </span>wave<span> travels through the medium until all its </span>energy is transferred<span>. In contrast, electromagnetic </span>waves<span> require no medium, but can still travel through one</span>
