Yeah, hand signals are important in officiating games. The hand signals are given by the referee who first signals the fault and then indicates which team has won the point. A point is indicated by one finger at the side of the court to indicate the winner of the rally.
Answer:
potential difference V= 300 volts
Explanation:
Given:
d= 2.0 cm = 0.02m
E = 15 kN/C = 15 × 10³ N/C
For a uniform field between two plates, the Electric Filed Intensity (E) is proportional to the potential difference (V) and inversely proportional to distance between the plates.
E= V/d
⇒ V= E×d = 15 × 10³ N/C × 0.02 m = 300 volts (∴1 Nm/C = 1 J/C= 1 volts)
They believe the distortions happened when two galaxies collided.
Hope This Helps :)
(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
Well, the acceleration is the difference of speeds divided by the time period.
.
One rev/s is
, so our final result is
.
