Answer:
v = -14 m/s
Explanation:
Given that,
Initial location of the ball, X₁ = 10 m
Final position of the ball, X₂ = -25 m
Time taken to travel is, t = 2.5 s
The average velocity of the ball is given by the formula,
V = X₂ - X₁ / t m/s
Substituting the values in the above equation,
V = -25 - 10 / 2.5
= -14 m/s
The negative sign in the velocity indicates that ball rolls in the opposite direction.
Hence, the average velocity of the ball is v = -14 m/s
Answer:

The Magnitude of electric field is in the upward direction as shown directly towards the charge
.
Explanation:
Given:
- side of a square,

- charge on one corner of the square,

- charge on the remaining 3 corners of the square,

<u>Distance of the center from each corners</u>


∴Distance of center from corners, 
Now, electric field due to charges is given as:

<u>For charge
we have the field lines emerging out of the charge since it is positively charged:</u>

<u>Force by each of the charges at the remaining corners:</u>

<u> Now, net electric field in the vertical direction:</u>


<u>Now, net electric field in the horizontal direction:</u>


So the Magnitude of electric field is in the upward direction as shown directly towards the charge
.
Answer:
The minimum inductance needed is 2.78 H
Explanation:
Given;
frequency of the AC, f = 26.5 Hz
the root mean square voltage in the circuit,
= 41.2 V
the maximum current in the circuit, I₀ = 126 mA
The root mean square current is given by;

The inductive reactance is given by;

The minimum inductance needed is given by;

Therefore, the minimum inductance needed is 2.78 H
Answer: be alert for pedestrians near the bus.
Explanation: Due to road accidents many Governments around the world has adopted and put in place certain rules and regulations with regards to road safety, this is so to prevent the or reduce the chances of accidents happening.
Road safety rules are rules and guidelines put in place by Government in order to prevent road accidents and maintain a free flow of traffic. An example of such rules is 'be alert for pedestrians near the bus ' when approaching a local bus that is stopped.
Answer:
T = 693.147 minutes
Explanation:
The tank is being continuously stirred. So let the salt concentration of the tank at some time t be x in units of kg/L.
Therefore, the total salt in the tank at time t = 1000x kg
Brine water flows into the tank at a rate of 6 L/min which has a concentration of 0.1 kg/L
Hence, the amount of salt that is added to the tank per minute = 
Also, there is a continuous outflow from the tank at a rate of 6 L/min.
Hence, amount of salt subtracted from the tank per minute = 6x kg/min
Now, the rate of change of salt concentration in the tank = 
So, the rate of change of salt in the tank can be given by the following equation,

or, 
or, T = 693.147 min (time taken for the tank to reach a salt concentration
of 0.05 kg/L)