Answer:
1.045 m from 120 kg
Explanation:
m1 = 120 kg
m2 = 420 kg
m = 51 kg
d = 3 m
Let m is placed at a distance y from 120 kg so that the net force on 51 kg is zero.
By use of the gravitational force
Force on m due to m1 is equal to the force on m due to m2.
3 - y = 1.87 y
3 = 2.87 y
y = 1.045 m
Thus, the net force on 51 kg is zero if it is placed at a distance of 1.045 m from 120 kg.
Answer:
D
Explanation:
Let’s calculate the kinetic energy for all of the choices.
a. (1/2)(100)(100)^2 = 50(10000)=500,000
b. (1/2)(100)(1)^2 = 50
c. (1/2)(10)(100)^2 = 5(10000) = 50,000
d. (1/2)(1)(1)^2 = 0.5
We can see that (d) has the least kinetic energy.
We can calculate the acceleration of Cole due to friction using Newton's second law of motion:
where
is the frictional force (with a negative sign, since the force acts against the direction of motion) and m=100 kg is the mass of Cole and the sled. By rearranging the equation, we find
Now we can use the following formula to calculate the distance covered by Cole and the sled before stopping:
where
is the final speed of the sled
is the initial speed
is the distance covered
By rearranging the equation, we find d:
Answer:
U = – 0.12J
Explanation:
Given N = 10 turns, I = 5A, r = 5×10-²m
B^ = 0.05 T iˆ+ 0.3 T kˆ
Magnitude of the magnetic field vector B = √(0.05²+0.3²) = 0.304T
Area = πr² = π(5×10-²)² = 7.85×10-³m²
Magnetic moment μ = NIA
μ = 10×5×7.85×10-³ = 0.3925Am²
U = -μ•B = –0.3925×0.304 = –0.12J
The sign is negative because the magnetic moment is aligned with the magnetic field.
