U = 0, initial vertical velocity
Neglect air resistance, and g = 9.8 m/s².
The time, t, required for the pen to attain a vertical velocity of 19.62 m/s is given by
19.62 m/s = 0 + (9.8 m/s²)*(t s)
t = 19.62/9.8 = 2.00 s
Answer: 2.0 s
Answer:
(a) 0.0178 Ω
(b) 3.4 A
(c) 6.4 x 10⁵ A/m²
(d) 9.01 x 10⁻³ V/m
Explanation:
(a)
σ = Electrical conductivity = 7.1 x 10⁷ Ω-m⁻¹
d = diameter of the wire = 2.6 mm = 2.6 x 10⁻³ m
Area of cross-section of the wire is given as
A = (0.25) π d²
A = (0.25) (3.14) (2.6 x 10⁻³)²
A = 5.3 x 10⁻⁶ m²
L = length of the wire = 6.7 m
Resistance of the wire is given as


R = 0.0178 Ω
(b)
V = potential drop across the ends of wire = 0.060 volts
i = current flowing in the wire
Using ohm's law, current flowing is given as


i = 3.4 A
(c)
Current density is given as


J = 6.4 x 10⁵ A/m²
(d)
Magnitude of electric field is given as


E = 9.01 x 10⁻³ V/m
Answer:
To obtain the power, we first need to find the work made by the force.
1) To calculate the work, we need the next equation:

So the force is given by the problem so our mission is to find 'dx' in terms of 't'
2) we know that:

So we have:

Then:

3) Finally, we replace everything:

After some calculation, we have as a result that the work is:
161.9638 J.
4) To calculate the power we need the next equation:

So
P = 161.9638/4.7 = 34.46 W
Answer:
Explanation:
The acceleration of an object down a slope (neglecting friction, µ = 0) is:
a = g × sin θ
Where,
g is the acceleration due to gravity and θ is the angle of the slope.
a = (9.8 × sin (21.5º)
= 3.592 m/s²
Using equations of motion,
S = ut + 1/2at²
Since, u = 0,
S = 1/2at²
347 = 1/2 × (3.592)t²
t² = 193.21
= sqrt(193.21)
= 13.9 s.
Thank you for posting your question here at brainly. I hope the answer will help. Below are the choices that can be found elsewhere:
<span>A. 1.5 * 10^3 Watts
B. 7.3 * 10^2 Watts
C. 3.5 * 10^2 Watts
D. 2.5 * 10^2 Watts
</span>
<span>Work = force*displacement = 10^2*87 = 8,700 joule
Power = work/time = 8,700/6 = 1.45*10^3 (rounded up to 1.5 kw). The answer is A. </span>