Answer:
When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation).
Explanation:
Answer: 
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed=
Joules
m= mass of copper = 454 g
c = specific heat capacity = 
Initial temperature of the copper =
= 23.0°C
Final temperature of the water =
= ?
Change in temperature ,
Putting in the values, we get:


The final temperature of copper will be 
Answer:
8N
Explanation:
Applied force - Frictional force = net force
The emf induced = B*l*v where B is the flux density, l the length of the conductor and v the velocity of the conductor. In the given case B = 0.035 N/amp.meter, l = 0.86 and v = 6 m/sec
emf = 0.035*0.86*6 = 0.1806 v ≈ 0.18 v
choice: D
Answer:
A line crossing the x-axis in a velocity-time graph means that the moving object has changed its direction.
Explanation:
Velocity-Time graph:
A velocity-time graph is a two dimensional graph with velocity at its y-axis and time at its x-axis. At any point, value of y represents the velocity and value of x represents the time. The slope of the graph gives us the acceleration or deceleration of the moving object.
In a velocity-time graph:
- A straight line represents constant velocity.
- A diagonal line means that the velocity of a body is changing.
*Referring to the figure attached with the answer*
The velocity of the moving object increases at a constant rate for the first 10 minutes. Then the velocity is 60 m/min for the next 5 minutes. After that the velocity is decreasing. Till 30th minute when the velocity is at 0 m/min.
What happens here?
Velocity is a vector quantity. It has some direction. In a velocity-time graph, we are only concerned with two directions of velocity:
- Forward direction
- Backward direction
So, the object stops at 30th minute and starts moving in the reverse direction after that with an increasing velocity. <u>The point where the line cuts the x-axis is basically the point where the object starts moving in the reverse direction.</u>