Questions from Modern Physics

Q: A falling brick has a mass of 1.5 kg and

A falling brick has a mass of 1.5 kg and is moving straight downward with a speed of 5.0 m/s. A 1.5-kg physics book is sliding across the floor with a speed of 5.0 m/s. A 1.5-kg melon is traveling wit...

Q: On December 27, 2004, astronomers observed the greatest flash of

On December 27, 2004, astronomers observed the greatest flash of light ever recorded from outside the solar system. It came from the highly magnetic neutron star SGR 1806-20 (a magnetar). During 0.20...

Q: A 20.0-kg rock is sliding on a rough

A 20.0-kg rock is sliding on a rough, horizontal surface at 8.00 m/s and eventually stops due to friction. The coefficient of kinetic friction between the rock and the surface is 0.200. What average p...

Q: A tandem (two-person) bicycle team must overcome a

A tandem (two-person) bicycle team must overcome a force of 165 N to maintain a speed of 9.00 m/s. Find the power required per rider, assuming that each contributes equally. Express your answer in wat...

Q: When its 75-kW (100-hp) engine is

When its 75-kW (100-hp) engine is generating full power, a small single-engine airplane with mass 700 kg gains altitude at a rate of 2.5 m/s (150 m/min, or 500 ft/min). What fraction of the engine pow...

Q: Your job is to lift 30-kg crates a vertical distance

Your job is to lift 30-kg crates a vertical distance of 0.90 m from the ground onto the bed of a truck. How many crates would you have to load onto the truck in 1 minute (a) for the average power outp...

Q: An elevator has mass 600 kg, not including passengers. The

An elevator has mass 600 kg, not including passengers. The elevator is designed to ascend, at constant speed, a vertical distance of 20.0 m (five floors) in 16.0 s, and it is driven by a motor that ca...

Q: A ski tow operates on a 15.0° slope of

A ski tow operates on a 15.0° slope of length 300 m. The rope moves at 12.0 km/h and provides power for 50 riders at one time, with an average mass per rider of 70.0 kg. Estimate the power required to...

Q: Two tugboats pull a disabled supertanker. Each tug exerts a constant

Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.80 × 106 N, one 14° west of north and the other 14° east of north, as they pull the tanker 0.75 km toward the north. Wha...

Q: You are applying a constant horizontal force

You are applying a constant horizontal force