Answer:
(a) 209 Watt
(b) 4482.8 seconds
Explanation:
(a) P = 50×4.18
Where P = rate of heat loss in watt
P = 209 Watt
Applying,
Q = cm(t₁-t₂)................ Equation 1
Where Q = amount of heat given off, c = specific heat capacity capacity of human, m = mass of the person, t₁ and t₂ = initial and final temperature.
From the question,
Given: m = 90 kg, t₁ = 40°C, t₂ = 37°C
Constant: c = 3470 J/kg.K
Substtut these values into equation 1
Q = 90×3470(40-37)
Q = 936900 J
But,
P = Q/t.............. Equation 2
Where t = time
t = Q/P............ Equation 3
Given: P = 209 Watt, Q = 936900
Substitute into equation 3
t = 936900/209
t = 4482.8 seconds
Answer:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as
Now by putting the values in the above equation ,then we get
η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
Answer: Truck 2, because it has a larger mass than truck 1 (and the same velocity)
Explanation:
We can write the kinetic energy of an object with mass M and velocity V as:
K = (M/2)*V^2
Let's calculate the kinetic energy for each truck:
Now, we can see that both trucks move at the same velocity, but truck 1 has a mass of 5000 pounds, while truck 2 has also a mass of 5000 pounds and an extra of 900 pounds.
Then the total mass of truck 2 is 5000 pounds + 900 pounds = 5900 pounds.
Then both trucks have the same velocity, and truck 2 has a larger mass than truck 1, this implies that truck 2 will have a larger kinetic energy than truck 1.
Answer:
Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves.
Explanation:
HOPE THIS HELPS!!!!!!❤️
A pendulum's time period is the amount of time it takes to complete one oscillation. The pendulum with a length of 3.98 m and a length of 99.4 cm will have a time period of 4 and 1.99 seconds, respectively.
<h3>What is the definition of a
simple pendulum?</h3>
A simple pendulum is a device with a point mass hanging from fixed support and connected to a light inextensible thread.
The vertical line going through the fixed support represents the mean position of a basic pendulum.
h = vertical distance from the point of suspension
L = length of the simple pendulum
The time period of the simple penduum is given by
For l = 3.98 m
T = 4 second
For l = 99.4 cm = 0.994 m
T = 1.99 second
The time period of the pendulum having 3.98 m and 99.4 cm in length will be 4 and 1.99 seconds respectively.
To learn more about the simple pendulum refers to the link;
brainly.com/question/14759840
