Answer:
The average speed can be calculated as the quotient between the distance travelled and the time needed to travel that distance.
To go to the school, he travels 2.4 km in 0.6 hours, then here the average speed is:
s = (2.4km)/(0.6 hours) = 4 km/h
To return to his home, he travels 2.4km again, this time in only 0.4 hours, then here the average speed is:
s' = (2.4 km)/(0.4 hours) = 6 km/h.
Now, if we want the total average speed (of going and returning) we have that the total distance traveled is two times the distance between his home and school, and the total time is 0.6 hours plus 0.4 hours, then the average speed is:
S = (2*2.4 km)/(0.6 hours + 0.4 hours)
S = (4.8km)/(1 h) = 4.8 km/h
Well depending on the speed of both of those things is were the rock will be placed and it also determines how fast can an environment change
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Answer:
d) 1.2 mT
Explanation:
Here we want to find the magnitude of the magnetic field at a distance of 2.5 mm from the axis of the coaxial cable.
First of all, we observe that:
- The internal cylindrical conductor of radius 2 mm can be treated as a conductive wire placed at the axis of the cable, since here we are analyzing the field outside the radius of the conductor. The current flowing in this conductor is
I = 15 A
- The external conductor, of radius between 3 mm and 3.5 mm, does not contribute to the field at r = 2.5 mm, since 2.5 mm is situated before the inner shell of the conductor (at 3 mm).
Therefore, the net magnetic field is just given by the internal conductor. The magnetic field produced by a wire is given by
where
is the vacuum permeability
I = 15 A is the current in the conductor
r = 2.5 mm = 0.0025 m is the distance from the axis at which we want to calculate the field
Substituting, we find:
D
Using the kinetic energy 1/2mv^2 formula
5*10^5 is the answer
Answer:
The gravitational potential energy of the ball is 13.23 J.
Explanation:
Given;
mass of the ball, m = 0.5 kg
height of the shelf, h = 2.7 m
The gravitational potential energy is given by;
P.E = mgh
where;
m is mass of the ball
g is acceleration due to gravity = 9.8 m/s²
h is height of the ball
Substitute the givens and solve for gravitational potential energy;
PE = (0.5 x 9.8 x 2.7)
P.E = 13.23 J
Therefore, the gravitational potential energy of the ball is 13.23 J.
