<span>So we want to know how much work is needed to move a charge Q=3C for a distance r=0.01m trough a potencial difference U=9V. Work of electric potential is defined as W=Q*U and we can now simply put in the numbers. We get: W=3C*9V=27J. So the correct answer is (2) 27J. </span>
Answer
given,
position of particle
x(t)= A t + B t²
A = -3.5 m/s
B = 3.9 m/s²
t = 3 s
a) x(t)= -3.5 t + 3.9 t²
velocity of the particle is equal to the differentiation of position w.r.t. time.

------(1)
velocity of the particle at t = 3 s
v = -3.5 + 7.8 x 3
v = 19.9 m/s
b) velocity of the particle at origin
time at which particle is at origin
x(t)= -3.5 t + 3.9 t²
0 = t (-3.5 + 3.9 t )
t = 0, 
t = 0 , 0.897 s
speed of the particle at t = 0.897 s
from equation (1)
v = -3.9 + 7.8 t
v = -3.9 + 7.8 x 0.897
v = 3.1 m/s
According to Newton's Second Law:
F = m*a = 2000 kg*3.5 m/s^2 = 7000 N
Answer:
Well,
Explanation:
In a wave, energy is transported without the transport of water. Basically, a wave can be described as a disturbance that travels through a medium, transporting energy from one location to another location without transporting matter.
W=F*S
W - Work
F - Force
S - Distance (from latin word 'spatium)
so...
S= 5 (m)
W=60 (J)
W=F*S
F=W/S
F=60/5=12 J/m = 12 N (Newtons)