Physics Force & Laws Of Motion Level: High School
A 50 kilogram student stands in an elevator . How much force does she exert on the elevator floor if it is moving upward at 1 meter per second squared ?
Physics Kinematics Level: High School
How long would it take an object dropped from the learning tower of Pisa (height 54.6 meters) to hit the ground . How fast was it traveling at the moment of impact ?
Physics Kinematics Level: High School
Define the term acceleration motion.Physics Force & Laws Of Motion Level: High School
A 292 kg motorcycle is accelerating up along a ramp that is inclined 31.5 degree above the horizontal . The propulsion force pushing the motorcycle up the ramp is 2740 N, and air resistance produces a force of 250 N that opposes the motion . Find the magnitude of the motorcycle’s acceleration
Physics Force & Laws Of Motion Level: High School
In the drawing at ‘click here’ , the weight of the box on the table is 396 N and that of the hanging block is 170 N. Ignore all frictional effects , and assume the pulley to be massless .a) Find the acceleration of the two blocks .
b) Find the tension in the cord.
Physics Force & Laws Of Motion Level: High School
The speed of a bobsled is increasing because it has an acceleration of 2.8 m/s^2. At a given instant in time. The force resisting the motion, including kinetic friction and air resistance , total 450 N . The mass of the bobsled and its riders is 220 kg .a) What is the magnitude of the force propelling the bobsled forward ?
b) What is the magnitude of the force acts on the bobsled ?
Physics Force & Laws Of Motion Level: High School
The helicopter in the figure at “click here” is moving horizontally to the height at a constant velocity, The weight of the helicopter is W = 50400 N . The lift force L generated by the rotating blade makes an angle of 21 degree with respect to the vertical .a) What is the magnitude of the lift force ?
b) Determine the magnitude of the air resistance R that oppose the motion.
Physics Force & Laws Of Motion Level: High School
A 4.10 kg box is sliding across the horizontal floor of an elevator . The coefficient of kinetic friction between the box and the floor is 0.470 . Determine the kinetic frictional force that acts on the box for each of the following cases .a) The elevator is stationary.
b) The elevator is accelerating upward with an acceleration whose magnitude is 1.30 m/s^2.
c) The elevator is accelerating downward with an acceleration whose magnitude is 1.30 m/s^2.
Physics Force & Laws Of Motion Level: High School
A 28 kg crate rests on a horizontal floor, and a 63 kg person is standing on the crate .a) Determine the magnitude of the normal force that the floor exerts on the crate .
b) Determine the magnitude of the normal force that the crate exerts on the person .
Physics Work,Power & Energy Level: High School
My professor likes to write a table for energy conservation (kinetic energy , gravitational potential energy , and total ). Why does the total always become the kinetic energy even though there is also the GPE ?
Physics Force & Laws Of Motion Level: High School
A system has m1 = 6 kg, I1 = 0.1 kg. m^2, r1 = 0.2 m, I2 = 0. 125 kg. m^2, and r2 = 0.25 m. The acceleration of m1 is 2m/s^2 downward .a) Draw a free body diagram for mass m1 and use it to find the tension T1.
b) Find the angular acceleration a1 and a2 of the pulleys p1 and p2 .
c) Draw a free body diagram for pulley P1 and use it to find T3.
d) Draw a free body diagram for pulley P2 and use it to find T2 .
Physics Work,Power & Energy Level: High School
A friend claims that he can hold on to a 11 kg child in a 64 mi/h collision lasting for 0.05 s as he has his seat belt on . To prove that the violent forces during a collision will tear the child from his arms , calculate the magnitude of the needed retarding force . (A child should always be in a toddler seat secured with a seat belt in the back seat of a car)
Physics Work,Power & Energy Level: High School
An 8.0 kg mass moving east at 15.6 m/s on a frictionless horizontal surface collides with a 10.0 kg object that is initially at rest . After the collision , the 8.00 kg object moves south at 3.90 m/s .a) What is the velocity of the 10.0 kg object after the collision ?
b) What percentage of the initial kinetic energy is lost in the collision ?
Physics Kinematics Level: High School
Relative Velocity
A car is traveling along a straight , level road at 11 m/s . When the car is 150 meters from a railroad crossing , the driver of the car realize a train is approaching . He accelerates at 1.5 m/s square in an attempt to cross the tracks before the train , Which is 100 meters from the crossing and traveling at 14 m/s . Does the car make it across the tracks before the train ? Justify .
Physics Work,Power & Energy Level: High School
A large asteroid is on a collision course with the earth , the mass of the asteroid is 5.0 x 10e9 metric tons and it is approaching at a velocity of 42000 km/hr. Calculate the kinetic energy of the asteroid in joules . The mass of the earth is 6 x 10e24 kg and g , the acceleration due to gravity is 9.8 m/s squared .