Consider a child who is swinging. As she reaches the lowest point in her swing:
a. the tension in the rope is equal to her weight.
b. the tension in the rope is equal to her mass times her acceleration.
c. her acceleration is downward at 9.8 m/s2.
d. none of the above.
Question 2
A roller coaster, loaded with passengers, has a mass of 3000 kg; the radius of curvature of the track at the bottom point of the dip is 24 m. If the vehicle has a speed of 18 m/s at this point, what force is exerted on the vehicle by the track? (g = 9.8 m/s2)
a. 2.3 104 N
c. 7.0 104 N
b. 4.7 104 N
d. 1.0 104 N
Because the leg muscles of children with muscular dystrophy are weak, they must perform the Gowers’
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