E = IR + Ir
I = $\frac{E}{R+r}$ = $\frac{2.0}{2.0 \times 0.5}$ = 0.8A
johnmulu answered the question on May 23, 2017 at 07:17
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The diagram in Fig. 2 represent an electric circuit in which five resistors are connected to be a battery of e.m.f. 4.0 V and of negligible internal resistance.
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Date posted: May 23, 2017. Answers (1)
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(ii) Explain how the value in part (a)(i) is obtained.
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State the:
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Date posted: May 16, 2017. Answers (1)
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Date posted: May 16, 2017. Answers (1)
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(II) On the mass;
(III) To overcome friction.
Date posted: May 16, 2017. Answers (1)
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Figure 9 shows a drum of mass 90 kg being rolled up a plane inclined at 25o to the horizontal. The force F applied is 420N and the distance moved by the drum along the plane is 5.2 m.
Determine:
(i) The work done by the effort;
(ii) The work done in raising the drum;
(iii) The efficiency of the inclined plane as a machine.
Date posted: May 16, 2017. Answers (1)
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State one reason why system B may have a higher efficiency than system A.
Date posted: May 16, 2017. Answers (1)
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Date posted: May 16, 2017. Answers (1)
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Date posted: May 16, 2017. Answers (1)
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Figure 12 shows a body of weight 50N placed on a surface which is inclined at an angle of 30o to the horizontal. The body experiences a maximum frictional force of 29 N with the surface.
Determine the force required to move the body, up the inclined with constant velocity
Date posted: May 16, 2017. Answers (1)
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Figure 13 shows a frictionless trolley of mass 2 kg moving with uniform velocity towards a wall. At the front of the trolley is a spring whose spring constant is 25 Nm-1. The trolley comes to rest momentarily after compressing after compressing the spring by 3 cm and the rebounds from the wall.
(i) Determine
(I) The force exerted on the wall by the spring.
(II) The maximum acceleration of the trolley as it rebounds from the wall.
(ii) State the reason why the trolley acquires a constant velocity after it rebounds
Date posted: May 16, 2017. Answers (1)
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Figure 12 shows a lorry towing a trailer using a rope.
The lorry exerts a force N on the trailer and the trailer exerts an equal but opposite force M on the lorry. The frictional force between the trailer and the road is F. Explain how the forces N, M and F enable the trailer to move
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Determine the terminal velocity of the body.
Date posted: May 16, 2017. Answers (1)
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Two identical spherical steel balls are released from the top of two tall jars containing liquids L1 and L2 respectively. Figure 3 shows the velocity-time graph of the motion of the balls.
Explain the nature of the curves and state why they are different.
Date posted: May 16, 2017. Answers (1)
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Explain this observation.
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Determine the distance traveled 3.0 seconds after the start.
Date posted: May 15, 2017. Answers (1)
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Explain how the ball attains the new path.
Date posted: May 15, 2017. Answers (1)
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Figure 9 shows a velocity-time graph for the motion of a body of mass 2 kg.
Use the graph to determine the:
(i) Displacement of the body after 8 seconds
(ii) Acceleration after point B;
(iii) Force acting on the body in part (a) (ii).
Date posted: May 15, 2017. Answers (1)
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Figure 2 shows a section of a curved surface ABCD. Point A is higher than Point B while BCD is horizontal. Part ABC is smooth while CD is rough. A mass m is released from rest at A and moves towards D.
State the changes in the velocity of m between:
(a) B and C;
(b) C and D;
Date posted: May 15, 2017. Answers (1)