A (field) hockey player is running north at a speed of 8 m⋅s−1.A ball is coming directly towards her from the north at a speed of18 m⋅s−1. She swings her stick forward, directly north, at a speedof 6 m⋅s−1 measured in her own frame of reference. What is thespeed of the ball with respect to the hockey stick?
Relative to the hockey stick, the ball is travelling at ____m⋅s−1.
Jane's brother Andrew leaves home for school at 8:00 am. Hewalks at 3.3 kph. At 8:20 am Jane discovers that Andrew has lefthis homework at home. She decides to follow him on her bicycle andgive him his homework, but she wants to be back home in time for anonline test at 9 am. What is the minimum constant speed at whichshe needs to ride? (Hint: At what time of day will they meet?)
Jane must ride at least ______ kph.
