Answer:
D
Explanation:
The decrease in potential energy is equal to the increase in kinetic energy.
mgh
250 x 9.8 x 30
=73, 500
I believe the answer would be 7.5 m/s^2
Answer:a) 34.5 N; b) 24.5 N; c) 10 N; d) 1J
Explanation: In order to solve this problem we have to used the second Newton law given by:
∑F= m*a
F-f=m*a where f is the friction force (uk*Normal), from this we have
F= m*a+f=5 Kg*2 m/s^2+0.5*5Kg*9.8 m/s^2= 34.5 N
then f=uk*N=0.5*5Kg*9.8 m/s^2= 24.5N
the net Force = (34.5-24.5)N= 10 N
Finally the work done by the net force is equal to kinetic energy change so
W=∫Force net*dr= 10 N* 0.1 m= 1J
Answer:
Fc = 89.67N
Explanation:
Since the rope is unstretchable, the total length will always be 34m.
From the attached diagram, you can see that we can calculate the new separation distance from the tree and the stucked car H as follows:
L1+L2=34m
Replacing this value in the previous equation:
Solving for H:
We can now, calculate the angle between L1 and the 2m segment:
If we make a sum of forces in the midpoint of the rope we get:
where T is the tension on the rope and F is the exerted force of 87N.
Solving for T, we get the tension on the rope which is equal to the force exerted on the car:
Calculate the magnetic field strength at the ground. Treat the transmission line as infinitely long. The magnetic field strength is then given by:
B = μ₀I/(2πr)
B = magnetic field strength, μ₀ = magnetic constant, I = current, r = distance from line
Given values:
μ₀ = 4π×10⁻⁷H/m, I = 170A, r = 8.0m
Plug in and solve for B:
B = 4π×10⁻⁷(170)/(2π(8.0))
B = 4.25×10⁻⁶T
The earth's magnetic field strength is 0.50G or 5.0×10⁻⁵T. Calculate the ratio of the line's magnetic field strength to earth's magnetic field strength:
4.25×10⁻⁶/(5.0×10⁻⁵)
= 0.085
= 8.5%
The transmission line's magnetic field strength is 8.5% of that of earth's natural magnetic field. This is no cause for worry.
