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Date : Y 2012/1-Midterm/N- 15 Acad. Year _2011-2012 Subject Physics Variant_6
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Three players on a reality TV show are brought to the center of a large, flat field(Fig.1). Each is given a meter stick, a compass, a calculator, a shovel, and (in a different order for each contestant) the following three displacements:
72.4 m, 32.00 east of north
57.3 m, 36.00 south of west
17.8 m straight south
The three displacements lead to the point where the keys to a new Porsche are buried. Two players start measuring immediately, but the winner first calculates where to go. What does she calculate?
Two cars, A and B, move toward each other at 10 m/s and 30 m/s on a straight highway. When they saw each other, both apply brakes at the same time. Car A slows down at an acceleration of 4 m/s2 and car B slows down at 6 m/s2. If the distance between them is 60 m, will they crash? If so, what is the speed of each car?
You are on the roof of the TTPU lyceum building, 46.0 m above the ground (Figure 2). Your physics professor, who is 1.80 m tall, is walking alongside the building at a constant speed of 1.20 m/s. If you wish to drop an egg on your professor's head, where should 1.80 m the professor be when you release the egg? Assume that the egg is in free fall.
If the brakes of a car can decelerate it at 5 m/s2, (a) What time is required to reduce the velocity of the car from 135 km/h to 45 km/ h? (b) How many meters does the car travel during this deceleration
A ball is thrown with the velocity v0 = 10 m/s at an angle of 450 to the horizon. Find: (1) the height h the ball will rise to, (2) the distance s from the point of throwing to where the ball will drop onto the ground, (3) the time during which the ball will be in motion
A sailor in a small sailboat encounters shifting winds. She sails 2.00 km east, then 3.50 km southeast, and then an additional distance in an unknown direction. Her final position is 5.80 km directly east of the starting point (Fig. 1). Find the magnitude and direction of the third leg of the journey. Draw the vector addition diagram and show that it is in qualitative agreement with your numerical solution.
A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 12 m/s, skates by with the puck. After 3.0 s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 4.0 m/s2, (a) how long does it take him to catch his opponent, and (b) how far has he traveled in that time? (Assume that the player with the puck remains in motion at constant speed.)
A daring 510-N swimmer dives off a cliff with a running horizontal leap, as shown in Fig. 2. What must her minimum speed be just as she leaves the top of the cliff so that she will miss the ledge at the bottom, which is 1.75 m wide and 9.00 m below the top of the cliff?
As a ship is approaching the dock at 45.0 cm/s, an important piece of landing equipment needs to be thrown to it before it can dock. This equipment is thrown at 15.0 m/s at 600 above the horizontal from the top of a tower at the edge of the water, 8.75 m above the ship's deck (Fig. 3.) For this equipment to land at the front of the ship, at what distance D from the dock should the ship be when the equipment is thrown? Air resistance can be neglected.
An object rolls down an inclined plane with a uniform acceleration of 2 m/s2. At a certain instant its velocity is 6 m/s.(a) What is the velocity of object 5 s later? (b) How far does it travel in that time interval
An airplane starting from airport A flies 300 km east, then 350 km at 30.00 west of north, and then 150 km north to arrive finally at airport B. (a) The next day, another plane flies directly from A to B in a straight line. In what direction should the pilot travel in this direct flight? (b) How far will the pilot travel in the flight? Assume there is no wind during either flight.
A ball is dropped from the top of a 40 m high building. At what initial velocity must a second ball be thrown from the top of the building 2 s later, such that both balls arrive at the ground at the same time?
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