The prefix your looking for is centi as in centimeter. I got this answer on google.
So please mark me as Brainiest.
Answer:
1807.56 kJ
Explanation:
Parameters given:
Current, I = 8.9A
Time, t = 4.7hrs = 4.7 * 3600 = 16920 secs
Voltage, V = 12V
Electrical energy is given as:
E = I*V*t
Where I = Current
V = Voltage/Potential differenxe
t = time in seconds.
E = 8.9 * 12 * 16920
E = 1807056 J = 1807.056 kJ
(a)
consider the motion of the tennis ball. lets assume the velocity of the tennis ball going towards the racket as positive and velocity of tennis ball going away from the racket as negative.
m = mass of the tennis ball = 60 g = 0.060 kg
v₀ = initial velocity of the tennis ball before being hit by racket = 20 m/s
v = final velocity of the tennis ball after being hit by racket = - 39 m/s
ΔP = change in momentum of the ball
change in momentum of the ball is given as
ΔP = m (v - v₀)
inserting the above values
ΔP = (0.060) (- 39 - 20)
ΔP = - 3.54 kgm/s
hence , magnitude of change in momentum : 3.54 kgm/s
The correct answer would be the last one
Centripetal force is equal to (mv^2)/r
The way I use to answer these question is to set every variable to 1
m=1
v=1
r=1
so centripetal force =1
then change the variable we're looking at
and since we're find when it's half we could either change it to 1/2 or 2, but 2 is easier to use
m=1
v=2
r=1
((1)×(2)^2)/1=4
So the velocity in the 1st part is half the velocity in the 2nd part and the centripetal force is 4× less
The answer is the centripetal force is 1/4 as big the second time around
