Answer: 52%
Explanation:
1W = 1 J/s
motor input is 10000 J/s
Potential energy change
PE = 955(9.81)(25.0) = 234,213.75
power needed to change the PE in that time
P = 234,213.75/ 45 = 5,204.75 Watts
motor is 5204.75 / 10000 = 0.520475 or 52% efficient
Answer:
0.39
Explanation:
In order not to slide, you must have exactly the same acceleration of the train:

where
g = 9.81 m/s^2
There is only one force acting on you: the static frictional force that "pulls" you forward, and it is given by

According to Newton's second law, the net force acting on you (so, the frictional force) must be equal to your mass times the acceleration, so we have

from which we find

so, the minimum coefficient of static friction must be 0.39.
Answer:
300 N
Explanation:
The net force acting on the arrow is given by Newton's Second Law:

where
m = 0.06 kg is the mass of the arrow
a = 5,000 m/s^2 is the acceleration of the arrow
Substituting the numbers into the equation, we find

Answer:
E= 8501.2
Explanation:
Given Data;
Speed = 10.6 km/s = 10.6*10^3 m/s
Magnitude = 0.802 T
The magnitude of the electric field is calculated using the formula;
q E = q v B
E = v B
= 10.6 *10^3 * 0.802
= 8501.2
The direction of the electric field will point along the negative z-axis