Answer:
Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.
Explanation:
Since horse is working steadily, the power experimented by the horse (), measured in watts, is at constant rate. Then, the work needed by the horse (
), measured in joules, is equal to that power multiplied by time (
), measured in seconds. That is:
(1)
If we know that and
, then the work needed for the horse is:
Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.
Answer: The trip takes
Explanation:
Velocity is the variation of the position of a body (distance traveled
) with time
:
In this case, the car travels a distance at a velocity
and we need to find the time it takes the trip.
Isolating :
Finally:
A) d. 10T
When a charged particle moves at right angle to a uniform magnetic field, it experiences a force whose magnitude os given by
where q is the charge of the particle, v is the velocity, B is the strength of the magnetic field.
This force acts as a centripetal force, keeping the particle in a circular motion - so we can write
which can be rewritten as
The velocity can be rewritten as the ratio between the lenght of the circumference and the period of revolution (T):
So, we get:
We see that this the period of revolution is directly proportional to the mass of the particle: therefore, if the second particle is 10 times as massive, then its period will be 10 times longer.
B)
The frequency of revolution of a particle in uniform circular motion is
where
f is the frequency
T is the period
We see that the frequency is inversely proportional to the period. Therefore, if the period of the more massive particle is 10 times that of the smaller particle:
T' = 10 T
Then its frequency of revolution will be:
Answer:
Explanation:
Q1 = 35 nC = 35 x 10^-9 C
m = 3.5 micro gram = 3.5 x 10^-9 Kg
d = 35 cm = 0.35 m
(a) The electrostatic force between the two charges is balanced by the weight of another charge.
F = m g
(b) By substituting the values
Q2 = 13.34 x 10^-12 C
Q2 = 0.0134 nC