Answer:
Q=+100kj,w=-15kj,Q=100kj,w=-62kj
Explanation:
when energy is exerted into a system work done is equal to zero .hence the system does work to the surrounding.
Answer:

Explanation:
given,
coefficient of kinetic friction, μ = 0.25
Speed of sled at point A = 8.6 m/s
Speed of sled at point B = 5.4 m/s
time taken to travel from point A to B.
we know,
J = F Δ t
J is the impulse
where F is the frictional force.
t is the time.
we also know that impulse is equal to change in momentum.

frictional force
F = μ N
where as N is the normal force
now,






time taken to move from A to B is equal to 1.31 s