Studied by 24 peopleA rocket is propelled upward with an acceleration of 25 m/s² for 5 s. After that time, the engine is shut off, and the rocket continues to move upward. The maximum height, in meters, that the rocket will reach is
1,100 m
A projectile is launched horizontally with a velocity of 25 m/s from the top of a 75 m height. How many seconds will the projectile take to reach the bottom?
3.91 s
A projectile is launched at a certain angle. After 4 s, it hits the top of a building 500 m away. The height of the building is 50 m. The projectile was launched at an angle of
14 degrees
The operator of a boat wishes to cross a 5 km wide river that is flowing east at 10 m/s. He wants to reach the exact point on the opposite shore 15 min after starting. With what speed and in what direction should the boat travel?
11.4 m/s at 26.6 degrees E of N
A stone is thrown horizontally with an initial speed of 10 m/s from a bridge. Assuming that the air resistance is negligible, how long would it take the stone to strike the water 80 m below the bridge?
4 s
A stone is thrown horizontally with an initial speed of 30 m/s from a bridge. What is the stone’s total speed with it enters the water 4 seconds later, assuming air resistance is negligible?
50 m/s
A 0.25 Kg mass is attached to a sting and swung in a vertical circle whose radius is 0.75 m. At the bottom of the circle, the mass is observed to have a speed of 10 m/s. What is the magnitude of the tension in the string at that point?
35.7 N
A car and driver have a combined mass of 1,000 kg. The car passes over the top of a hill that has a radius of curvature equal to 10 m. The speed of the car at that instant is 5 m/s. What is the force of the hill on the car as it passes over the top?
7,300 N up
A spring with a stiffness constant k= 50 N/m has a natural length of 0.45 m. It is attached to the top of an incline that makes a 30 degree angle with the horizontal. The incline is 2.4 m long. A mass of 2 kg is attached to the spring, causing it to be stretched down the incline. How far down the incline does the end of the spring rest?
0.646 m
A force of 20 N acts horizontally on a mass of 10 kg being pushed along a frictionless incline that makes a 30 degree angle with the horizontal. The magnitude of the acceleration of the mass up the incline is equal to…
3.17 m/s²
What is the value of g at a height above Earth’s surface that is equal to the radius of Earth?
2.45 N/kg
What is the orbitals velocity of a satellite at a height of 300 km above the surface of Earth? (The mass of Earth is approximately 6e24, and its radius is 6.4e6
7.7 × 10^6 m/s
A 60 cm rope is tied to the handle of a bucket which is then whirled in a vertical circle. The mass of the bucker is 3 kg. At the lowest point in its path, the tension in the rope is 50 N. What is the speed of the bucket?
2 m/s
A 60 cm rope is tied to the handle of a bucket which is then whirled in a vertical circle. The mass of the bucker is 3 kg. What is the critical speed below which the rope would become slack when the bucket reaches the highest point in the circle?
2.4 m/s
The dwarf planet Pluto has 1/500 the mass and 1/15 the radius of Earth. What is the value of g (in m/s²) on the surface of Pluto?
225/50 m/s²
Which of the following is an expression for mechanical power?
F²t/m
An engine maintains constant power on a conveyer belt machine. Ig the belt’s velocity is doubled, the magnitude of its average acceleration…
Is halved
A 0.3-kg mass rests on top of a spring that has been compressed by 0.04 m. Neglect any frictional effects, and consider the spring to be massless. Then, if the spring has a constant k equal to 2,000 N/m, to what height will the mass rise when the system is released?
0.54 m
A satellite is currently orbiting Earth in a circular orbit of radius R; its kinetic energy is K1. If the satellite is moved and enters a new circular orbit of radius 2R, what will be its kinetic energy?
K1/2
An object of mass m is traveling at constant speed v in a circular path of radius r. How much work is done by the centripetal force during one-half of a revolution?
0
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