Есептер шығару бойынша 9 сынып физика материалы

Problem solving

1. Find the acceleration of an object experiencing a force 120 N, as shown in the picture.

2.If the mass of the object in problem 3 is 2 kg, find the acceleration of the object for each case.

3.A 2 kg object accelerates from rest to 5 m/s in 0.4 s. What is the net force on the object?

4.What is the gravitational force acting on two men, one weighing 80 kg and the other weighing 90 kg, who are standing 3 meters away from each other?

5. 5kg rocket emits 0.5kg of gas at 100 m/s. What is speed of rocket?

6. 200 gram smartphone falls on the floor from height of 1.5 meters. What is potential energy?

7.What are the following amounts of energy in joules?

1kJ= ?

10 MJ= ?

8.If the speed of a 20 g bullet which is shot out of a gun is 200 m/s, what is the kinetic energy of the bullet?

9.If a spring has a spring constant of 800 N/m, find its potential energy when it is compressed by 10cm,20cm.

10.An archer places an arrow in a bow and pulls the bowstring 60cm back from its equilibrium position, by applying a force of 300 N.Find the spring constant?

11.What does the momentum of an 18 g bullet which moves at a velocity of 250 m/s?

12. What does the momentum of an electron, having a mass of 9.1*10-31 kg, which moves at a velocity of 200 km/s?

13. 2 kg balls moving with velocities of 4 m/s and 2 m/s on a smooth horizontal surface undergo a head on inelastic collision. What is the common velocity of the balls after the collision?