1.3. Mass and weight
A subsection of Physics, 5054, through 1. Motion, forces and energy
Listing 10 of 86 questions
A bucket of water is pulled up out of a well using a rope. shows the rope winding on to a cylinder as the handle is turned. rope cylinder bucket 0.12 m 0.40 m axle axle handle The empty bucket has a mass of 1.0 kg. Complete the sentences that describe mass by filling in the gaps. The mass of a body is a measure of the amount of in the body. It resists a change in the state of of the body. When the bucket is full, it contains 2.4 × 10–2 m3 of water. The gravitational field strength g is equal to 10 N / kg. Explain what is meant by a gravitational field. The density of water is 1000 kg / m3. Determine the total weight of the bucket and the water. weight = The radius of the cylinder is 0.12 m and the handle is 0.40 m from the axle of the cylinder. The weight of the bucket and the water produce a moment that acts on the cylinder. Calculate this moment. moment = Calculate the minimum force on the handle that balances this moment. force = A farmer pulls the bucket of water up at a constant speed. He needs to exert a force on the handle that is greater than that calculated in . He notices that there is a slight increase in temperature where the axle is in contact with the frame holding it. Suggest two reasons why the force exerted is greater than the value calculated. 1. 2. State the energy changes that are taking place as the bucket is being lifted at a constant speed. State what can be deduced about the forces acting on the bucket when it is travelling upwards at a constant speed.
5054_w18_qp_21
THEORY
2018
Paper 2, Variant 1
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A sky-diver jumps from a stationary balloon. His initial downwards acceleration is 10 m / s2. shows the directions of the air resistance and the weight of the sky-diver. weight air resistance The mass of the sky-diver is 60 kg and his weight is 600 N. Explain, using ideas about the forces, why his initial downwards acceleration is 10 m / s2. When the parachute opens, the sky-diver experiences an upward acceleration for a short time. Explain why. The total force of air resistance on the sky-diver and open parachute changes with their speed, as shown in . speed m / s air resistance / N After the parachute opens, the sky-diver slows down to a terminal velocity. The weight of the sky-diver is 600 N. Using , determine the terminal velocity of the sky-diver. terminal velocity = Calculate the resultant force on the sky-diver when his speed is 5.5 m / s. resultant force =
5054_s16_qp_21
THEORY
2016
Paper 2, Variant 1
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Questions Discovered
86