Hi
I think the answer is:
GRAVITATIONAL POTENTIAL ENERGY TRANSFORMS INTO KINETIC ENERGY.
HOPE IT HELPS.
Answer:
a) 2.5 m/s. (In the opposite direction to the direction in which she threw the boot).
b) The centre of mass is still at the starting point for both bodies.
c) It'll take Sally 12 s to reach the shore which is 30 m from her starting point.
Explanation:
Linear momentum is conserved.
(mass of boot) × (velocity of boot) + (mass of sally) × (velocity of Sally) = 0
5×30 + 60 × v = 0
v = (-150/60) = -2.5 m/s. (Minus inicates that motion is in the opposite direction to the direction in which she threw the boot).
b) At time t = 10 s,
Sally has travelled 25 m and the boot has travelled 300 m.
Taking the starting point for both bodies as the origin, and Sally's direction as the positive direction.
Centre of mass = [(60)(25) + (5)(-300)]/(60+5)
= 0 m.
The centre of mass is still at the starting point for both bodies.
c) The shore is 30 m away.
Speed = (Distance)/(time)
Time = (Distance)/(speed) = (30/2.5)
Time = 12 s
Hope this Helps!!!
B - antidepressant (anti meaning against)
Explanation:
Sorry english only. I wished I answer that
Answer:2987.7 J
Explanation:
Given
sled weight is 
Tension in rope 
Time interval 
velocity of sled 
here speed is equal to velocity which is constant therefore acceleration is zero
thus 
Distance traveled in 

considering surface to be friction less
thus
will do work on sled



