Answer:
a useful sporting analogy ... Teachers of science routinely use analogies to help ... balls over the bar and you will probably find that.
Answer:
(A) it's acceleration is negative but but it's velocity is positive
Explanation:
In the question it is given that begins to slow down so its speed is decreasing it is does not means that its speed is negative
For example let first the velocity of the car is 30 m/sec and when its velocity decreases it becomes 20 m/sec in 5 sec
So it is not negative at all
Now the acceleration is the rate of change of velocity


So acceleration is negative here
So option (a) will be the correct option
Free fall condition : acceleration is constant downward and equals to gravitational acc.(g)
because velocity has opposite direction to acceleration, velocity will decrease as it rises.
Answer:
I = 4.75 A
Explanation:
To find the current in the wire you use the following relation:
(1)
E: electric field E(t)=0.0004t2−0.0001t+0.0004
ρ: resistivity of the material = 2.75×10−8 ohm-meters
J: current density
The current density is also given by:
(2)
I: current
A: cross area of the wire = π(d/2)^2
d: diameter of the wire = 0.205 cm = 0.00205 m
You replace the equation (2) into the equation (1), and you solve for the current I:

Next, you replace for all variables:

hence, the current in the wire is 4.75A
The student must have made an error in her measurement in the concentration of hydrogen ion in the basic solution given. From her measurement, the concentration is 1 × 10−3 M. If we calculate the pH, we get:
pH = -log ( 1 × 10−3) = 3
A pH of 3 does not signifies a basic solution it is in the acidic range. So, the measurement is wrong.