The answer would be B.
(V=IR, 12-10i, 12/10=1.2)
Answer:
9 hr
Explanation:
Speed = distance/time
Let the time taken by the train be t.
=> 70 = 630/t
=> t = 630/70
=> t = 9
it take 9 hr to complete its journey
Answer: B
Explanation:
The equation to find momentum is velocity*mass. Without velocity, there would be no momentum. Therefore the object CAN NOT be at rest.
A. The average force exerted on the ball during the serve is 57 N
B. The resistive force, given the data is -1125 N
<h3>A. How to determine the average force</h3>
- Mass (m) = 57 g = 57 / 1000 = 0.057 Kg
- Initial velocity (u) = 50 m/s
- Time (t) = 0.05 s
- Acceleration (a) = u / t = 50 / 0.05 = 1000 m/s²
- Force (F) = ?
F = ma
F = 0.057 × 1000
F = 57 N
<h3>B. How to determine the resistive force</h3>
- Mass (m) = 3000 Kg
- Initial velocity (u) = 72 Km/h = 72 / 3.6 = 20 m/s
- Final velocity (v) = 18 Km/h = 18 / 3.6 = 5 m/s
- Time (t) = 40 s
- Force (F) = ?
F = m(v – u) / t
F = 3000(5 – 20) / 40
F = -1125 N
Learn more about momentum:
brainly.com/question/250648
#SPJ1
Answer: The electric field is given in three regions well defined; 0<r<2; 2<r<4; 4<r<5 and r>5
Explanation: In order to solve this problem we have to use the gaussian law in the mentioned regions.
Region 1; 0<r<2
∫E.ds=Qinside the gaussian surface/ε0
inside of the solid conducting sphere the elevctric field is zero because the charge is located at the surface on this sphere.
Region 2; 2<r<4;
E.4*π*r^2=8,84/ε0
E=8,84/(4*π*ε0*r^2)
Region 3; 4<r<5
E=0 because is inside the conductor.
Finally
Region 4; r>5
E.4*π*r^2=(8,84-2.02)/ε0