2. How long will it take for a ball thrown vertically upward with an initial velocity of
1 answer:
You might be interested in
Answer: The velocity at different marked time points are given as
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
Explanation:
The slope of the tangent of the curve indicates the instantaneous velocity. So if the slope of the tangent is positive, that Is, the tangent makes a positive angle (above the horizontal axis) with the horizontal
axis, then the velocity at this point is positive, and if the slope of the tangent is negative, that is the tangent makes a negative angle with the horizontal axis (below the horizontal axis), then the velocity at this point is negative.
When the tangent of the line is parallel to the horizontal axis, the velocity is 0.
From the position-time graph attached, the sign on the instantaneous velocity for each time marked on the graph is given below
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
QED!
Answer:
The option (b) is correct.
Explanation:
The expression for the power in terms of work done is as follows;
Here, W is the work done, t is the time taken and P is the power.
According to the given problem, six identical resistors are connected in series with a battery. The number of joules per second supplied by the battery is then determined.
The expression for the equivalent resistance in the series combination is as follows;
R_{eq}=R_{1}+R_{2}......+R_{6}
Put R_{1},R_{2}......,R_{6}=R.
R_{eq}=R+R+R+R+R+R
R_{eq}=6R
It is given in the problem that a seventh resistor is added (in series).
R_{eq}=R_{1}+R_{2}......+R_{7}
Put R_{1},R_{2}......,R_{7}=R.
R_{eq}=R+R+R+R+R+R+R
R_{eq}=7R
The expression for the power in terms of voltage and resistance is as follows;
Here, R is the resistance.
From the above expression, it can be concluded that the power, the number of joules per second supplied by the battery is inversely proportional to the resistance. The equivalent resistance increases if the seventh resistance is connected with a battery.
If a seventh resistor is added (in series) the number of joules per second supplied by the battery decreases.
Therefore, the option (b) is correct.