Physics Force & Laws Of Motion Level: High School
. A force of magnitude P pushes the block foward and downward . Assume the force is applied at an angle of 37 degrees below the horizontal .a) Find the acceleration of the block as a function of P .
b) If P = 5.0 N find the acceleration and the friction force exerted on the block .
c) If P = 10.0 N find the acceleration and then the friction force exerted on the block .
d) Is there a definite minimum acceleration for the block ? If so , what is it ? Is there a definite maximum ?
Physics Force & Laws Of Motion Level: High School
conservation ofnmomentun
As a concerned citizen, you have volunteered to serve on a committee investigating injuries to middle school students participating in sports programs . Currently your committee is investigating the high incidence of ankle injuries on the basketball team . You are watching the team practice , looking for activities which can result in large horizontal forces on the ankle . Observing the team practice jump shots gives you an idea , so you try a small calculation . A 40- kg student jumps 1.0 meters straight up and shoots the 0.80 kg basketball at his highest point . From the trajectory of the basketball , you deduce that the ball left his hand at 30 degree from the horizontal at 20 m/s . What is the horizontal velocity when he hits the ground ?
Physics Force & Laws Of Motion Level: High School
Consider a lawnmower of weight w which can slide across a horizontal surface with a coefficient of friction (u) . In this problem the lawnmower is pushed using a massless handle , which makes an angle (theta) with the horizontal . Assume that Fh , the force exerted by the handle , is parallel to the upward . Find the magnitude , Fh, of the force required to slide the lawnmower over the ground at constant speed by pushing the handle .
Physics Force & Laws Of Motion Level: High School
A 200 g object is moving in a circle of radius 4m with a uniform speed of 6 m/s . What is the net force acting on the object ?
Physics Force & Laws Of Motion Level: High School
Impulse
A 300 g baseball traveling at 30 m/s is struck by a bat in the direction from which it came at 40 m/s find the impulse of the force on the baseball ?
Physics Force & Laws Of Motion Level: High School
The magnitude of the momentum of a particle is 32 kg m/s at a certain instant . If the velocity has a magnitude of 20 m/s at that instant , What is the mass of the particle ?
Physics Force & Laws Of Motion Level: High School
When an alpha particle is ejected from a nucleus , the nucleus then has lessa)mass
b) charge
c) both of these
d) neither of these
Physics Force & Laws Of Motion Level: High School
Rocket Propulsion
Model rocket engines are by thrust , thrust duration ,and total impulse , among other characteristics. A size C5 model rocket engine has an average thrust of 5.26 N, a fuel mass of 12.7 g , and an initial mass of 25.5 g . the duration of its burn is 1.90 s .a) what is the average exhaust speed of the engine ?
b) If this engine is placed in a rocket body mass 53.5 g, what is the final velocity of the rocket if it is fired in outer space ? Assume the fuel burns at a constant rate .
Physics Force & Laws Of Motion Level: High School
Impulse
A 300 g ball with a speed v of 6.0 m/s strikes a wall at an angle theta = of 30 degree and then rebounds with the same speed and the angle , it is in contact with the wall for 10 ms . In unit-vector notation , what area) the impulse on the ball from the wall ?
b) the average force on the wall from the ball ?
Physics Force & Laws Of Motion Level: High School
Impulse
It is well known that bullets and other missiles fired at superman simply bounce off his chest . Suppose a gangster says superman’s chest with 3 g bullet at the rate of 100 bullets/min, and the speed of each bullet is 500 m/s . Suppose too that the bullets rebound straight back with no change in speed . What is the magnitude of the average force on superman’s chest from the stream of bullets ?
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
A shell is shot with an initial velocity v0 of 20 m/s , at an angle of (theta) = 60 degrees with the horizontal . At the top of the trajectory , the shell explodes into two fragments of equal mass . One fragment , whose speed immediately after the explosion is zero , falls vertically , How far from the gun does the other fragment land , assuming that the terrain is level and that air drag is negligible ?
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
Two government agents (FBI agents Mulder and Scully) need your physics expertise to determine why an alien spaceship exploded . The wreckage of the spaceship is in three large pieces around a western Nebraska town . The center of mass of one piece (mass = 300 kg ) of the spaceship landed 6.0 km due north of the center of town . Another piece (mass = 1000 kg) of the spaceship landed 6.0 km due north of the center of town . Another piece (mass = 1000 kg) landed 1.6 km to the southeast (36 degrees south of east ) of the center of town . The last piece (mass = 400 kg) landed 4.0 km to the southwest (65 degrees south of west) of the center of town. There are no more pieces of the spaceship. The army, which was watching the spaceship on its radar, claims it was hovering motionless over the center of town when the spaceship spontaneously exploded and the pieces fell to the ground . Agents Mulder and Scully do not believe that the spaceship exploded on its own accord . They think a missile hit it . They ask you to determine whether the fragments found are consistent with the spaceship exploding spontaneously, if not, determine from what direction the missile came . (For simplicity, assume that the pieces of the spaceship after the explosion are moving horizontally,)
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
A certain nucleus at rest spontaneously disintegrates into three particles . Two of them are detected . One has mass 16.7 x 10^-27 kg and velocity 6 x 10^8 m/s in the x-direction, the second has a mass 8.35 x 10^-27 kg and velocity 8 x 10^6 m/s in the y-direction . a) The mass of the third particle is 11.7 x 10^-27 kg ,what is the velocity ? b) How much energy is converted into kinetic energy by the disintegration process ?
Physics Force & Laws Of Motion Level: High School
Impulse
A girl of mass 50 kg throws a ball of mass 0.1 kg against a wall . The ball strikes the wall horizontally with a speed of 20 mls , and it bounces back with this same speed . The ball is in contact with the wall 0.05 s . What is the average force exerted on the wall by the ball ?a) 16 N
b) 20 N
c) 32 N
d) 40 N
e) 80 N
Physics Force & Laws Of Motion Level: High School
In the set up shown at “click here” , m = 1.20 kg , Theta = 20.0 degrees , Ignore friction .a) If the block is in static equilibrium , what is the tension in the spring ?
b) The string brakes and the clock slides through a rough patch on the incline that is 1.00 m long . If the coefficient of kinetic friction is 0.200 , how long it takes the block to slide through the rough patch ?
