Answer:
W = 0
Explanation:
We are given with, a construction worker is carrying a load of 40 kg over his head and is walking at a constant velocity. He travels a distance of 50 m.
The work done by an object is given by :
F = ma
So,
m is mass
a is acceleration
d is displacement
The worker is moving with constant velocity, its acceleration will be 0. So, the work done by the worker is 0.
As the steam touches the skin, it undergoes a phase change and releases latent heat due to the phase change. As it reaches equilibrium, it releases sensible heat. We calculate as follows:
Q = latent heat + sensible Heat
Q = 2.26 kJ / g (50.0 g) + 50.0 g ( 4.18 J / g C) (37 C - 100 C) ( 1 kJ / 1000 J)
Q = 99.833 kJ
Answer:
R1 = 5.13 Ω
Explanation:
From Ohm's law,
V = IR............... Equation 1
Where V = Voltage, I = current, R = resistance.
From the question,
I = 2 A, R = R1
Substitute into equation 1
V = 2R1................ Equation 2
When a resistance of 2.2Ω is added in series with R1,
assuming the voltage source remain constant
R = 2.2+R1, and I = 1.4 A
V = 1.4(2.2+R1)................. Equation 3
Substitute the value of V into equation 3
2R1 = 1.4(2.2+R1)
2R1 = 3.08+1.4R1
2R1-1.4R1 = 3.08
0.6R1 = 3.08
R1 = 3.08/0.6
R1 = 5.13 Ω
Answer:
1.15 m/s
Explanation:
Part of the question is missing. Found the missing part on google:
"1. A hanging mass of 1500 grams compresses a spring 2.0 cm. Find the spring constant in N/m."
Solution:
First of all, we need to find the spring constant. We can use Hooke's law:
where
is the force applied to the spring (the weight of the hanging mass)
x = 2.0 cm = 0.02 m is the compression of the spring
Solving for k, we find the spring constant:
In the second part of the problem, the spring is compressed by
x = 3.0 cm = 0.03 m
So the elastic potential energy of the spring is
This energy is entirely converted into kinetic energy of the cart, which is:
where
m = 500 g = 0.5 kg is the mass of the cart
v is its speed
Solving for v,