Answer:
Negative z-direction.
Explanation:
We need to determine the direction of the magnetic force. Since the velocity of the proton is in the positive x direction, and the magnetic field is in the positive y direction, we know by the vectorial formula
(or, alternatively, with the <em>left hand rule</em>) that the magnetic force points in the positive z-direction (also taking into account that <u>the charge is positive</u>), so the electric field should be in the negative z-direction to balance it.
In most compartment fires, the energy release in fire is directly proportional to the amount of oxygen available for combustion.
Answer: Option B
<u>Explanation:</u>
A fire is the chemical outcome of energy generated by the heat. So, this heat is generating fire due to friction between the heating source with igniting elements. And to increase the chain reaction of fire leading to combustion or fire require oxygen. So, the amount of oxygen will lead to the production of fire. Thus, the energy released by fire will be equal to the amount of oxygen available for combustion.
If there is no oxygen, then the fire will get succumbed. The fire consumes the oxygen present to increase the pace and spread of fire. So the consumed oxygen utilized for converting the simple fire to combustion will be equal to the release of energy in fire. Thus, energy released in fire is directly proportional to the amount of oxygen available for combustion.
Answer:

Explanation:
= Rate at which the distance between A and starting point of B is changing = -20 km/h
= Rate at which the distance of B is changing = 15 km/h
= Rate at which the distance between A and B is changing
Time after which the rate at which the distance between A and B is changing is 4 hours
Distance covered by A in 4 hours = 
a = Distance remaining to the start point of B = 
b = Distance covered by B in 4 hours = 
Distance between A and B after 4 hours


Differentiating with respect to time we get

The rate at which the distance between the ships is changing at 4 PM is
.
Answer:
The answer is: measuring instrument
Explanation:
The researcher develops test to measure the variables she is interested in. So, they are her measuring instrument.
Answer:
1. A
2. C
3. A
4. B
Explanation:
A conductor allows electric current to pass through it. Hence, when conductors are connected in a closed circuit, current flows.
All the resistors in Q2 are connected in series. In a series connection, the current across all the resistors is the same.
In a battery, chemical energy is converted to electrical energy by chemical reactions.
When a new resistor is connected in parallel to a circuit the current increases accordingly.