1) Displacement: -49 m, in the negative direction
Explanation:
The displacement of an object is a vector, whose magnitude is given by the difference between the final point of the motion and the starting point:

In this problem, the starting point is +34 m, while the final position is -15 m; therefore, the displacement is:

and the direction is negative, in according to the negative sign.
2) Velocity: -3.27 m/s
Explanation:
Velocity is equal to the ratio between the displacement and the time taken:

in this problem, we have:
d = -49 m is the displacement
t = 15 s is the time
therefore, the velocity is

and the direction is negative.
Answer:
D
Explanation:
Scientists use significant figures to avoid claiming more accuracy in a calculation than they actually know.
Answer:
The volume of water evaporated is 199mL
Explanation:
Concentration is calculated with the following formula

where n is the number of moles of solute and V is the volume of the solution (in this case is the same as the solvent volume) in liters.
So we isolate the variable n to know the amount of moles, using the volume given in liters


Now, we isolate the variable V to know the new volume with the new concentration given.

Finally, the volume of water evaporated is the difference between initial and final volume.

Assume the snow is uniform, and horizontal.
Given:
coefficient of kinetic friction = 0.10 = muK
weight of sled = 48 N
weight of rider = 660 N
normal force on of sled with rider = 48+660 N = 708 N = N
Force required to maintain a uniform speed
= coefficient of kinetic friction * normal force
= muK * N
= 0.10 * 708 N
=70.8 N
Note: it takes more than 70.8 N to start the sled in motion, because static friction is in general greater than kinetic friction.