Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of

Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is

with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
You can increase the capacitance of a capacitor by decreasing the plate spacing (A) or by increasing the area of the plates (D).
'A' and 'D' both do the job, so the correct choice is<em> (E)</em> .
Weight = Mass * gravity
= 1470* 9.8 = 14406 N ≈ 14,400 N
Answer:
I = 0.25 [amp]
Explanation:
To solve this problem we must use ohm's law which tells us that the voltage is equal to the product of the current by the resistance.
V = I*R
where:
V = voltage [Volt]
I = amperage or current [amp]
R = resistance [ohm]
Since all resistors are connected in series, the total resistance will be equal to the arithmetic sum of all resistors.
Rt = 2 + 8 + 14
Rt = 24 [ohm]
Now clearing I for amperage
I = V/Rt
I = 6/24
I = 0.25 [amp].
Positive. The 1st object loses electrons and will thus have an imbalance of charge with loss of electrons.