Answer:
The power of the kettle is P = 1 watt.
Explanation:
The definition of power is:
Power equals the quotient between work and time, or:
P = w/t.
In this case, we know that the work is:
w = 1J
And the time is:
t = 1 s
Then the power will be:
P = 1J/1s = 1 J/s
Also knowing that:
1 J/s = 1 W
(w is the unit for Watt)
We can conclude that the power of the kettle is:
P = 1 W
Answer:
θ = 45º
Explanation:
To find the solution, let's use the projectile launch equation
R = vo² sin 2θ / g
Where vo is the initial speed of the dolphin, T is the angle of the jump and g the gravity acceleration.
To obtain a maximum range, the sine T function must be 1,
sin 2θ = 1
2θ = sin⁻¹ 1
2θ = 90
θ = 45º
Therefore, the dolphin should jump at an angle of 45º from the horizontal
I'll take the gravitational constant G to be 6.67x10^-11 in this. I will also be using the mass of the earth as 5.972x10^24 (there might be a way to solve this without knowing the mass of the Earth but it has escaped me, if anyone wants to help me out on this then feel free).
We can calculate the gravity of the earth at the distance above it using
g=mG/r^2
Substituting in, we get
g=(5.972x10^24)x(6.67x10^-11)/(6380000+8960000)^2
=1.69 to 3sf
We also know that w=mg, so the weight of the astronaut is w=76x1.69=128.44N = 128N to 3sf
Answer:
3 Ω
Explanation:
I find a calculator with a reciprocal key quite useful for calculating parallel resistance.
Req = 1/(1/r1 +1/r2 +... +1/rn))
Of course, resistors in series add.
The far right two branches are 10 Ω in parallel with (8+2) Ω = 10 Ω. Of course, the parallel combination of two equal-value resistors is half the value of either of them. Thus the two right branches resolve to 5 Ω, which is then added to 1 Ω to give an effective middle section that is 12 Ω || 4 Ω || 6 Ω.
That combination has an effective resistance of ...
Req = 1/(1/12 +1/4 +1/6) = 1/(1/12 + 3/12 +2/12)) = 12/6 = 2 . . . ohms
This is effectively in series with the upper left 1 Ω resistor, so the equivalent load on the source is 1+2 = 3 Ω.
Answer:
C) 200 m/s
Explanation:
The sound travels a total distance of 360 m in 0.03 minutes.
v = (360 m) / (0.03 min × 60 s/min)
v = 200 m/s