-9.8 m/s^2 would be right.
<span>the formula q = 375 g * 25 C * 4.186 J / (g*C) = 39,243.75 J q represents the heat in Joules , m the mass in grams, difference of temperature in Celsius degree, and 4.186 J/(g*C) is the specific heat of water( I assume the water is in liquid from and will remain liquid). Approximately 39.24 kJ once you round and transform to kJ..1 kJ=1000J</span>
F = kq1q2/r²
F = 9.0(10^9)(10)(50)/20²
F = 1.125 * 10^10 N
Force = (mass) x (acceleration)
= (275kg) x (-4.5 m/s²) = -1,237.5 newtons.
In order for this mass to experience acceleration of -4.5 m/s²,
it must be pushed by -1,237.5 newtons of force, otherwise
it will not have that acceleration.
The plus and minus signs are completely your choice. The
positive direction is the direction you decided to call positive
when you started working with the problem. Chances are,
you probably called the positive direction the one in which
the object is already moving. That makes the acceleration
positive if the object is speeding up, negative if it's slowing
down.
If the acceleration is positive (speeding up), that means the
object is being pushed by a force in the same direction it's
already moving. If the acceleration is negative (slowing down),
that means the object is being pushed by a force opposite to
the direction it's already moving ... the negative direction.
Initial velocity, u = 0
Final velocity, v = 60 m/s (at take off)
Duration of the acceleration, t = 4 s
Calculate average acceleration.
a = (v - u)/t
= (60 m/s)/(4 s)
= 15 m/s²
Calculate the distance traveled during acceleration.
s = ut + (1/2)*a*t²
= 0.5*(15 m/s²)*(4 s)²
= 120 m
Answer: 120 m