Question 5
Marks: 0/1 An animal-rescue plane flying due east at 17.8 m/s drops a bale of hay from an altitude of 58 m. If the bale of hay has a mass of 6.9 kg, what is the magnitude of the momentum of the bale the moment before it strikes the ground? Express your answer in kg*m/s, to two significant figures.
Answer:
Incorrect
Marks for this submission: 0/1. This submission attracted a penalty of 0.5.Question 6
Marks: --/1 An animal-rescue plane flying due east at 19.5 m/s drops a bale of hay from an altitude of 70 m. If the bale of hay has a mass of 5.4 kg, what is the direction of the momentum of the bale the moment before it strikes the ground? Express your answer as a positive angle to the vertical, in degrees, to two significant figures.
Answer: Question 7
Marks: --/1 A 78-kg dancer leaps 20.8 cm high. As the dancer lands, his knees bend, lengthening the stopping time to 50 ms. Find the average force exerted on the dancer's body. Express your answer in N, to two significant figures.
Answer: Question 8
Marks: --/1 A 3.3 x 10-1 kg ball of dough is thrown straight up into the air with an initial speed of 4.6 m/s. Find the momentum of the ball of dough halfway to its maximum height on the way up. Express your answer in kg*m/s, to 2 significant figures.
Answer: Question 9
Marks: --/1 A moving object has a kinetic energy of 70 J and a momentum with a magnitude of 19.5 kg*m/s. What is the speed of the object, in m/s, to two significant figures?
Answer: Question 10
Marks: --/1 During a serve, a tennis racket exerts an average force of 192 N on a 60 g tennis ball, for 4.2 ms. If the ball is at rest before the impulse, what is the kinetic energy of the ball just afterward? Express your answer in J, to two significant figures.
Answer:
