Answer:
v = 57.2 m/s
Explanation:
The average velocity of the train can be defined as the total distance covered by the train divided by the time taken by the train to cover that distance. Therefore, we will use the following formula to find the average velocity of the train:
v = s/t
where,
s = distance covered = 460 km = (460 km)(1000 m/1 km) = 4.6 x 10⁵ m
t = time taken to cover the distance = 2 h 14 min
Now, we convert it into minutes:
t = (2 h)(60 min/1 h) + 14 min
t = 120 min + 14 min = (134 min)(60 s/1 min)
t = 8040 s
Therefore, the value of velocity will be:
v = (4.6 x 10⁵ m)/8040 s
<u>v = 57.2 m/s</u>
Answer:
A drop in voltage occurs
Explanation:
When electric current flows through a conduct, there are three basic electrical effects that occur to the conductor;
1. A magnetic field is set up around the conductor,
A magnetic field is formed around a conductor when current flows through it which makes it acts like a magnet. Application is used in electric bells.
2. Heat is generated, and
The heating effect of current is due to the conversion of some of the electrical energy that passes through the conductor, into heat energy. Application of heat effect include electric iron, microwave oven, electric bulb, hair straightener etc.
H = I²Rt
3. A drop in voltage occurs
Voltage drop is as a result of current passing through the impedance offers by the conductor or circuit elements. When current passes through a conductor, the resistance offers opposition to the flow of the electric current according to Ohm's law.
Answer:
Explanation:
The work done is defined as the product of force applied in the direction of displacement and the displacement.
W = F x d x Cosθ
where, F is the force applied, d be the displacement and θ be the angle between the displacement and force.
For the normal forces, the angle between the displacement and the force applied is 90 degree, and the value of Cos 90 is zero, so the work done is zero.
<u>We call changes between solid liquid and gaseous forms of a substance as phase change or change of state.</u>
<u>Explanation:</u>
To change a substance from one state to another, extreme temperatures or pressures are required. Sometimes when a substance doesn't change states we should use all the ideas when that happens. To create a solid, we should decrease the temperature by a huge amount and then add pressure. For example, oxygen will solidify at -361.8 degrees Fahrenheit at standard pressure. However, it will freeze at warmer temperatures when the pressure is increased.
Phase changes happen when a substance reach some special points. Sometimes when a liquid becomes a solid a freezing point or melting point is used to measure the temperature at which a liquid changes into a solid. Some of the phase changes are: Condensation, Freezing, Melting.
Answer:
Positive z direction.
Explanation:
The magnetic force acting on the electron is given by the formula as :
q is the charge on proton
v is the speed of proton
B is the magnetic field
It is mentioned that the proton is moving with a velocity in the positive x-direction. The uniform magnetic field B in the positive y-direction such taht,
q = +e
v = vi
B = Bj
Since, 
So, the magnetic force acting on the proton in positive z axis. Hence, the correct option is (d) "positive z direction".
