Question

Two ice skaters collided while moving toward each other on the ice. Examine the data:

Skater Direction Mass Acceleration after colliding
#1 Moving to the right 42 kg
1.5 m/s2 to the left

#2 Moving to the left unknown unknown
Two Students are asked to find the force exerted by the first skater on the second skater. Student A claims the force is equal to 63 Newtons. Student B argues that there is not enough information to find the answer. Explain which Student, A or B is correct and state how you know. You may refer to the STAAR Reference Materials, use the Desmos Calculator if you need to,and review Newton's Laws on your NTG to support your answer.

(2 points)


0 / 10000 Word Limit
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Answer 1

Student A is correct.

Reason: Newton’s 2nd law gives the net force on skater 1: Fnet = m a = 42 kg × 1.5 m/s^2 = 63 N (to the left). By Newton’s 3rd law the force skater 1 exerts on skater 2 is equal in magnitude and opposite in direction, so skater 1 pushes skater 2 with 63 N (to the right).

(Only caveat: this assumes no other horizontal forces besides the collision force are significant—on ice that’s the usual assumption.)