Chapter 6 Physics Homework
The total momentum of a flock of identical birds could be zero only if the birds are
flying in different directions
A slowly moving ship can have a greater momentum than a fast moving racing car when
its mass times velocity is greater than that of the car
How much impulse stops a 60-kg carton sliding at 5 m/s when it meets a rough surface
Impulse = change in momentum J = 60 kg x 5 m/s = 300 N*s
What impulse occurs when an average force of 15 N is exerted on a cart for 2.2 s
Impulse = force x time = 15 N x 2.2 s = 33 kg* m/s
What is the momentum of a 9-kg bowling ball rolling at 2.6 m/s
Momentum = mass x velocity = 9 (2.6) = 23 kg*m/s
Cassy can get more force on the bricks she breaks with the blow of her bare hand when
her hand is made to bounce from the bricks
Follow through is important in golf because it results in a greater
impulse on the ball
A 5.2-kg fish swimming 0.90 m/s swallows an absentminded 1.0-kg fish swimming toward it at a speed that brings both fish to a halt immediately after lunch. Find the speed of the approaching smaller fish before lunch.
initial momentum = final momentum (zero) v2= v1(m1/m2) = .9(5.2/1.0) = 4.7 m/s
A same-size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater
momentum
The quantity that is called impulse can be measured by the
product of force and time
When a big fish swims into an oncoming smaller fish and swallows it, the momentum of the two-fish system
remains the same
The speed of a 4 kg ball with the momentum of 12 kg*m/s is
speed = momentum/mass = 12/4 = 3 m/s
A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is
twice
In which is momentum conserved: an elastic collision or an inelastic collision
Momentum is conserved in both
An ostrich egg of mass m is tossed at a speed v into a sagging bed sheet and is brought to rest in a time t. Part A: Find the force acting on the egg when it hits the sheet Part B: If the mass of the egg is 0.90 kg , its initial speed is 1.7 m/s , and the time to stop is 0.20 s, find the average force on the egg.
Part A: Force = mass x velocity / time Part B: (.9 x 1.7) / .2 = 7.7 N
When two vehicles collide, momentum is conserved
whether the collision is elastic or inelastic