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A 32Okg wooden raft floats on a lake. When a 75kg man stands on the raft, it sinks 3.5cm deeper into the water. When he steps off, the raft oscillates for a while.
i. What is the frequency of oscillation?
ii. What is the total energy of oscillation (ignoring damping)?
a) Suppose a cargo truck's rope and puiley system lowers a cocoa bag, having a total mass of 90.0 kg, down a 60.0° slope at constant speed. The coetficient of friction between the bag
and the ground is 0.100.
i) How much work is done by friction as the bag moves 30.0 m along the hill?
i) How much work is done by the rope on the bag in this distance?
A typical scuba tank, when fully charged, contains 12.0L of air at 204atm. Assume an empty tank contains air at 34atm and is connected to an air compressor at sea level. The air compressor intakes air from the atmosphere, compresses it to high pressure, and then inputs this high-pressure air into the scuba tank.
Assume the tank remains at the same temperature as the surrounding air during the filling process. If the average flow rate of air from atmosphere into the intake port of the air compressor
is 290L/min, how long will it take to fully charge the scuba tank?
A 1000 kg car running at 50 km/h eastward has head-on collision with a 2000 kg truck running at 30 km/h. If the two vehicles are locked together after collision, calculate the final velocity of the wreckage. What is the loss in kinetic energy of the system?
A 70 gram bullet moving east at 400 m/s strikes a 1.3 kg pendulum block on the right and becomes embedded on it. How high will the block-bullet rise above its original position?
what is the average speed of the object?
why does this compound turn from a semiconductor into a conductor?
What is a good explanation for the perovskite compound Cs8Pb8I24 being a semiconductor?
But by replacing 2 Pb with In & Bi (Cs8(InBi)Pb6I24) the compound becomes a conductor with zero bandgap
Later on, if you replace all Pb with In & Bi (Cs8(In4Bi4)I24) the compound is semiconductor again but with a much smaller bandgap than the original compound.
Can anyone help me on how to explain this, please?
At the instant, the traffic light turns green, a truck with a constant velocity of 12 m/s. At the same moment, the car begins to accelerate at 1 m/s^2. when it reaches 20 m/s, the car continues at this velocity. When does the car pass the truck? How far have they gone from the traffic light?
