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Questions A |
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1 |
A drawing pin whose point has a cross-sectional area of 0.11 mm2 is used to pin a notice to a tree, the wood of which requires a pressure of 2000 MPa for penetration. Calculate the force needed. |
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| 2 |
The pd supply in the flashgun for a camera is 1.4 V. When the gun fires, a charge of 890 mC flows through the bulb. Calculate the energy released. |
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| 3 |
Calculate the mass of gold in a bar of volume 240 cm3. The density of gold is 19300 kg/m3 |
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| 4 |
An engineer needs to apply a torque (moment) of 15 Nm to a nut. His spanner is 14 cm long. Calculate the force he must exert on the end of the spanner. |
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| 5 |
A light bulb is only 2% efficient, the wasted energy being turned into thermal energy (heat). Calculate how much electrical energy must be supplied if 3 J of light energy are to be obtained. |
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| 6 |
In a lightning stroke about 21 MC flows in some 4.7 ms. Calculate the current. |
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| 7 |
A spring used in a mattress has a stiffness of 67 N/m. Calculate the force that will compress it by 6.3 cm. |
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| 8 |
Calculate the work done in driving a post into the earth if a force of 17 kN is exerted over a distance of 3.2 cm |
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| 9 |
A weather balloon occupies 58 m3 at ground level where the pressure is 103 kPa. It rises to a region where the pressure is only 82 kPa. Calculate the new volume. |
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| 10 |
Calculate the kinetic energy possessed by an air rifle pellet of mass 6.5 g if it emerges from the barrel at 150 m/s. |
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| 11 |
Calculate the weight on the moon of a feather whose mass is 3.4 g. The gravitational field strength on the moon is 1.6 N/kg. |
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| 12 |
An arrow reaches it's target 200 m away in 3.2 s. Calculate the velocity. |
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| 13 |
Calculate the potential energy gained by a mountaineer of mass 125 kg as he ascends Mount Everest, which is 8.8 km high |
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| 14 |
A rocket of mass 3400 kg is powered by motors capable of a net driving force of 1.8 kN. Calculate the rocket's acceleration. |
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| 15 |
A racing car achieves a speed of 30 m/s over the first 3.2 s. Calculate the acceleration |
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| 16 | Calculate the magnification produced by a lens when it is forming a clear image on a screen 13 m away from a slide positioned 5.3 cm away from the lens. | Answer |
| 17 | Calculate the angle of a ray in glass when light enters at an angle of 48.0o. Glass has a refractive index of 1.52 | Answer |