Question

a mother and daughter press their hands together and then push apart while ice skating. mother 100 kg 15 n 15 n daughter 50 kg immediately after they push away from each other, how does the motion of the mother and daughter change? the mother moves forward, and the daughter moves backward with a greater acceleration both move forward, but the mother moves with a greater acceleration the mother moves backward, and the daughter moves forward with a greater acceleration both move backward, but the daughter moves with a greater acceleration

Explanation:

Step1: Apply Newton's third - law

According to Newton's third - law, the forces on the mother and daughter are equal in magnitude and opposite in direction. The mother exerts a 15 N force on the daughter, and the daughter exerts a 15 N force on the mother.

Step2: Apply Newton's second - law ($F = ma$)

For the mother, $F_m=15N$, $m_m = 100kg$, so $a_m=\frac{F_m}{m_m}=\frac{15}{100}=0.15m/s^2$. For the daughter, $F_d = 15N$, $m_d=50kg$, so $a_d=\frac{F_d}{m_d}=\frac{15}{50}=0.3m/s^2$. The forces are in opposite directions, so they will move in opposite directions. The mother will move in one direction and the daughter in the opposite direction. Since $a_d > a_m$, the daughter has a greater acceleration.

Answer:

D. Both move backward, but the daughter moves with a greater acceleration