An Olympic skier moving at 20.0 m/s down a 30.0o slope encounters a region of wet snow, of coefficient of friction μk = 0.740. How far down the slope does she go before stopping?

a.119 m

b.145 m

c.170 m

d.199 m

Option B

Explanation:

Forces acting on the skier-

F1 down the slope  

F2

F3 = friction force    

Net force, down the slope  

Acceleration m/s2  

Acceleration remains constant, initial speed is 20 m/s

Speed at time t is m/s

Distance down the slope at time t is

When the skier stops, her speed is 0. Thus,  

, seconds

Distance travelled in 14.5 seconds (negative because it is down the slope).

Option B is correct

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.