Question

1. A wave completes 20 cycles in 8 seconds. The frequency of the wave is .

a) 2.5 Hz

b) 160 Hz

c) 0.4 Hz

2. The electric face between two charged particles is F . As the double the distance between the two charges , the new force will be .

a) F/2

b) F/4

c) 2F

d) 4f

3. Two objects are on the right end of a seesaw . object A (m=10 kg ) is 20 cm away from the fulcrum and object B ( m =15 kg is 10 cm away from the fulcrum . Where would object C (m - 20 kg ) need to be placed to balance the seesaw.

a) 17.5 cm to the right

b) 17.5 cm to the left

c) 30 cm to the right

d) 20 cm to the left

4. Mike's car is initially moving at 25 m/s . He slams on his brakes as he approached a red light. If it took his car 4 second to come a full stop , find the car's acceleration.

a) 6.25 m/s²

b) -6.25 m/s²

c) 100 m/s ²

d) -100m/s²

5. A ball  is cropped from rest . Find the speed of the ball after 4.2 seconds has passed

a) 4.2 m/s

b) 9.8 m/s

c) 41.2 m/s

d) 19.5 m/s

6. A 4-cm tall object is placed 24 cm in from of a converning lens with a formal length of 18 c, . The height of the image is

a) -4 cm

b) 4 cm

c) 12 cm

d) -12cm.

b) 4 cm

c) 12 cm

d) -12 cm.

7. A 100 - Watt light bulb is connected to a 120 -volt power supply . Find the current flow through the light bulb.

a) 1.2 A

b) 0.83 A

c) 100 A

d) 12.000A

Answer 1