QUIZ 3  “Nota”  means none of the above

 

  1. A person can survive a feet-first impact at a speed of about 12 m/s on concrete. What speed can a person survive a feet-first impact on water ?

(a)  10 m/s (b) 34 m/s   (c) 9 m/s    

 

  1. A lunar vehicle is tested on the Moon at of 12 km/h. When it travels at 12 km/h on Earth, its momentum is

(a) greater than on the moon     (b) less than on the moon (c) the same as on the moon (d) nota

 

  1.  What is the magnitude of the impulse needed to stop  a 20-kg bowling ball moving at 3 m/s?

      (a) 3 kg m/s   (b) 20 kg m/s   (c)  60 kg m/s (d) nota


       4.  A car crashes into a wall at 25 m/s and is brought to rest in 0.1 second. What is the average

             force exerted on a 10–kg test dummy by the seat belt?

      (a) 2500 N      (b)  250 N   (c)  25N    (d) nota

 

   5.  A diesel engine  weighs  3 times as much as a freight car. If the diesel engine coasts at 1 km/h  into freight- car initially at rest, how fast do the two coast after they couple together (stick together) ?

(a)     4/3 km/h  (b) 3/4 km/h (c) 1  km/h   (d) nota

 

  6.  When the velocity of an object is tripled, by what factor is the momentum changed ?

 (a)  1/3   (b) 9  (c)  3   (d) nota

 

  7. When the velocity of an object is tripled, by what factor is the kinetic energy (KE)  changed ?    
  (a) 1/3 (b)  9  (c) 3 (d) nota

 

  8.  A what point in its motion is the KE of a pendulum a maximum?

  (a) at the highest point    (b) at the lowest point  (c) nota

 

  9. A what point in its motion is the PE (potential energy)  of a pendulum a maximum?

  (a) at the highest point    (b) at the lowest point  (c) nota


 10. What produces the greater change in KE: exerting a 10-N force for a distance of 5 m , or exerting a 20–N force for  a distance of 2.5 m ?

 (a) exerting a 10-N force for a distance of 5 m    (b) exerting a 20–N force for a distance of 2.5 m     (c) both the same  (d) nota