Physics Force & Laws Of Motion Level: High School
A 3.0 kg mass is sliding on a horizontal frictionless surface with a speed of 3.0 m/sec when it collides with a 1.0 kg mass initially at rest as shown in the figure at “click here” . The masses stick together and slide up a frictionless circular track of radius 0.40 m . To what maximum height , h, above the horizontal surface will the masses slide ?
Physics Rotational Mechanics Level: High School
Conservation of momentum
A 2.0 kg object moving 3.0 m/sec strikes a 1.0 kg object initially at rest . Immediately after the collision at the 2.0 kg object has a velocity of 1.5 m/sec directed 30 degrees from its initial direction of motion . What is the y component for the velocity of the 1.0 kg object just after collision ?
Physics Rotational Mechanics Level: High School
Centre of mass
Three particles are placed in the xy plane . A 30 gram particle is located at (3,4) m , and a 40 gram particle is located at (-2,-2) m . Where must a 20 gram particle be placed so that the center of mass of the three particle system is at the origin ?
Physics Force & Laws Of Motion Level: High School
Conservation of momentum
An astronaut outside a spaceship hammers a loose rivet back in place . What happens to the astronaut as he swing the hammer ?
Physics Force & Laws Of Motion Level: High School
A pitcher claims he can throw a baseball with as much momentum as a 3.00 gram bullet moving with a speed of 1500 m/sec . A baseball has a mass of .145 kg . What must be its speed if the pitcher’s claim is valid ?
Physics Force & Laws Of Motion Level: High School
Conservation of momentum
A u-238 nucleus (mass = 238 units) decays , transforming into an alpha particle (mass = 4 units) and a residual thorium nucleus (mass = 234 units) if the uranium nucleus was at rest , and the alpha particle has a speed of 1.5 x 10^7 m/sec , determine the recoil speed of the thorium nucleus . Include a sketch in your solution .
Physics Force & Laws Of Motion Level: High School
A child bounces a 50 gram superball on the sidewalk . The velocity of the superball changes from 21 m/sec downward to 19 m/sec upward . If the contact time with the sidewalk is 1/800 sec , What is the magnitude of the force exerted on the superball by the sidewalk ?
Physics Properties Of Matter Level: High School
Liquids
A small Dutch boy, Hansel and his little sister Gretel were walking home from school along a polder when they saw a stream of water squirting horizontally from a hole in the dyke . Hansel used a meter stick and found that the hole was a distance Y1 = 116.3 cm above the polder and that the water landed a distance X1 = 1.52 meters from the base of the dyke. Hansel sent Gretel running from help and stuck his finger. (cross sectional area A1 = 1.00 cm^2) into the hole . While Hansel waved for help , he used the physics he learned in Kindergarten to calculatea) Time, T, the water is in the air .
b) The distance of the hole , Y2, below the surface of the North sea .
c) The velocity , V0, x, of the water as it exits the hole .
d) The velocity ,V, of the water as it hits the polder .
e) The cross sectional area , A, of the stream of water as it hits the Polder .
Physics Kinematics Level: High School
Circular Motion
Two physics students , Joe and Willie , decided to fling balloons filled with M1 = 68.5 grams of ice water at coeds who are sun bathing on the roof of a sorority house two blocks east of the physics building at UC Berkley . Joe and Willie built a Trebuchet of the roof of the physics building . For the large Mass , M2, they has a solid lead sphere D2 = 20.7 cm in diameter. M1 was mounted so that its center mass is at a distance L1 = 4.27 M from the axis of rotation and M2 was mounted so that its center of mass was L2 = .238 M from the axis of rotation . Assume that the Trebuchet is loaded in the horizontal position , and that the balloon leaves the arm at the highest point of rotation . Ignore friction , the moments of inertia of arms , etc . A) Calculate the mass of the lead sphere M2 ? B) Calculate the maximum angular velocity achieved by the Trebuchet W mass ? C) Calculate the tangential velocity with which the balloon begins its flight Vt ?
Physics Force & Laws Of Motion Level: High School
Atilla (mass M1 = 4.03 kg ) has fallen into a well . A freak earthquake has set the water in the well spinning (W1 = 4.03 Rad/sec) about a vertical axis thus carrying Atilla around and around . The radius of the well is R1 = 20.6 cm. Calculate atilla’s centripetal acceleration , Ac , the centripetal force on Atila, Fc, and Atilla’s tangential velocity , V1 .
Physics Kinematics Level: High School
Minnie Mouse (mass m1 = 48.7 g) has run to the top of a curved frictionless wedge (height H1 = .79 m) . She slides down the track makes a perfectly elastic collision with Mickey Mouse (mass M2 = 56.3 g) who is at rest . Mickey files off the table (height H2 = .921 M) above the floor and Minnie rebounds to the height H3 before she eventually falls off the table . A) How far from the edge of the table does Mickey land ? B) How high does Minnie rebound ? C) How far from the edge of the table does Minnie land ?
Physics Force & Laws Of Motion Level: High School
On the day of accident my partner and I repaired the chimney of a 20 meter call building .When we completed our work we noticed we had some bricks left over on the roof . To get them down we put them in a barrel, I then tied the rope to my truck . I swung the barrel out and loaded it with bricks. When we united the rope I was jerked off the ground suddenly lost my presence of mind , and forgot to let go of the rope . I proceeded up the side of the building at a rapid pace . At the third floor I meet the barrel which was now proceeding downward at an impressive rate, causing serious injury. Slowed only slightly by my collision with the barrel , I continued my rapid ascent , not stopping until my fingers of my right hand were two knuckles deep into the pulley. I was able to hold lightly onto the rope spite the excruciating pain I was experiencing , at this same time the barrel hit the ground and all the bricks fell out of the bottom. As you can imagine I began a very rapid descent down the building. Again at the 3rd floor I meet the barrel again , however this time the barrel slowed me down just enough to lessen my injuries when I fell onto the pile of bricks. As I layed on the pile of bricks I let go of the rope, only to see the barrel fall six storied right on top of me .I have a mass of M1 = 72.1 kg
Barrel has mass of M2 = 22.9 kg
Bricks have mass M3 = 99.9 kg.
The pulley has mass M4 = 14.4 kg
The pulley has radius R = .31 meter.
Calculate how long it took this accident to run its course. Assume that all collisions with the barrel occur at 10.0 meters . Assume further that all collisions stop the motion for an instant and that all subsequent motion begin with zero initial velocity
Physics Kinematics Level: High School
A 75.0 kg person stands on a scale in an elevator . What does the scale read (in N and in kg) when the elevator is(a) at rest
(b) ascending at a constant speed of 3.0 m/s.
(c) falling at 3.0 m//s
(d) accelerating upward at 3.0 m/s squared .
(e) accelerating downward at 3.0 m/s squared.
Physics Kinematics Level: High School
Police investigator examining the scene of an accident involving two cars , measure 72 m long skid marks of one of the cars . Which nearly came to a stop before colliding . The coefficient of kinetic friction between rubber and the pavement is about 0.80 . Estimate the initial speed of that car assuming level road .
Physics Kinematics Level: High School
A projectile is launched from ground level to the top of a cliff which is 195 m away and 155 m high . If the projectile lands on top of the cliff 7.6 s after it is fired , find the initial velocity of the projectile (magnitude and direction) Neglect air resistance .