Newton's law of motion Questions and Answers

Dr. John Paul Stapp was a U.S. Air Force officer who studied the effects of extreme deceleration on the human body. On December 10, 1954, Stapp rode a rocket sled, accelerating from rest to a top speed of 282 m/s (1015 km/h) in 5.00 s, and was brought jarringly back to rest in only 1.40 s! Calculate his acceleration and deceleration. Express each in multiples of g (9.80 m/s2) by taking its ratio to the acceleration of gravity. (a) acceleration g (b) deceleration (Enter the magnitude.) g

A box sits on a plane that is tilted 25° above the horizontal. A horizontal force of 30N acts on the box. Use trigonometry to write the force in vector component form using (a) a standard coordinate system, and (b) a coordinate system tilted to align itself with the plane.

Determine the applied force needed to stretch the spring 6.5, 7.0, 7.5, and 8.0 cm. Record in your table the displacement and applied force in each case( in centimeters).

A 12-kg object experiences a constant Net Force of (-)36 N. Which of the following is closest to the acceleration experienced by the object? * a. -432 m/s/s b. - 3 m/s/s c. - 4 m/s/s d. 0 m/s/s

(3) The same net force F from problem 1 is now acting on an object of unknown mass. The acceleration of the object from F is equal to 3a. What is the mass of the object in terms of m? * a.m b. 3m c. ½ m d. Cannot be determined from the information provided.

A person ties a rope to a box and pulls the box to the right. The block slides along the floor at a constant speed. There is a friction force between the box and the floor (the coefficient of kinetic friction is <1). Draw the box's free-body diagram. Label the types of forces (e.g., normal, friction, weight, etc.) and use appropriate subscripts to indicate the object exerting the force and the object feeling the force. The lengths of your arrows should be qualitatively correct (e.g., if two forces have the same magnitude, then their arrows should be the same length).

You have to lift a 15 kg object. What is your output force? Using a lever, you push down 20 N to lift a 10 kg object. A) Find the output force. B) What is the input force? C) How much does the ramp multiply your force? You push with 10 N up a ramp to move a 40 N object to the top of a table. By how much does the ramp multiply your force?

In the figure shown, a wedge is being moved on a horizontal smooth surface with a velocity 'v' as shown. At the instant shown, if angular velocity of rod of length xv/l where x is a rational number What is the value of (1/1-x)? (sin37° = 3/5)

A 4.4 kg firework moving with a velocity of 10.3 m/s to the right explodes in mid-air into two pieces. One of the exploded pieces has a mass of 1.5 kg and a velocity of 16.0 m/s to the right. What is the speed of the other piece?

A 60-kg woman stands on a light, cubical box that is 5 cm on each edge. The box sits on the floor. What pressure does the box exert on the floor?

What is the magnitude of the Impulse delivered by a baseball hit of a force of 1,941 N for a contact time of 0.00461 s?

Running on a treadmill is slightly easier than running outside because there is no drag force to work against Suppose a 60 kg runner completes a 5.0 km race in 18 minutes. Assume the density of air is 1.20 kg/m². (A) Determine the drag force on the runner during the race. Suppose that the cross section area of the runner is 0.72 m². (B)What is this force as a fraction of the runner's weight?

What force is required to speed up a 1,090 kg car from a speed of 4.7m/s to a speed of 14.7m/s in 13.3 s?

Ned the skydiver weighs 600 N and has a mass of 60 kg. How large must be the force of air resistance acting on Ned in order that Ned will maintain an unchanging speed while falling through the air?

A 600-N uniform rectangular sign 4.00 m wide and 3.00 m high is suspended from a horizontal, 6.00-m-long, uniform, 150-N rod as indicated in the figure below. The left end of the rod is supported by a hinge and the right end is supported by a thin cable making a 30.0° angle with the vertical. (Assume the cable is connected to the very end of the 6.00-m-long rod, and that there are 2.00 m separating the wall from the sign.) (a) Find the (magnitude of the) tension T in the cable. (b) Find the horizontal and vertical components of the force exerted on the left end of the rod by the hinge. (Take up and to the right to be the positive directions. Indicate the direction with the sign of your answer.)

A 580-N uniform rectangular sign 4.00 m wide and 3.00 m high is suspended from a horizontal, 6.00-m-long, uniform, 140-N rod as indicated in the figure below. The left end of the rod is supported by a hinge and the right end is supported by a thin cable making a 30.0° angle with the vertical. (Assume the cable is connected to the very end of the 6.00-m-long rod, and that there are 2.00 m separating the wall from the sign.) (a) Find the (magnitude of the) tension T in the cable. (b) Find the horizontal and vertical components of the force exerted on the left end of the rod by the hinge. (Take up and to the right to be the positive directions. Indicate the direction with the sign of your answer.)

A boy is pulling a load of 150 N with a string inclined at an angle of 30° to the horizontal. If the tension in the string is 105 N, the force tending to lift the load off the ground is: (sin 30° =1/2 cos 30° =√3/2and tan 30° =1/√3)

A man standing on level ground tries to drag a 705 N log behind him by exerting a horizontal force of 323 N. If the coefficients of static and kinetic friction are 0.475 and 0.321 respectively, a) Draw a Free-Body Diagram for the log. b) Calculate the maximum friction force. Does the man move the log? If not, how much force does friction exert on the log?

1. A 975 kg car with a velocity of 10.0 m/s accelerates constantly to 25.0 m/s in 2.50 seconds. a) (10 pnts) Find the car's initial momentum. b) (10 pnts) Find the car's final momentum. c) (10 pnts) Find the Net impulse acting on the car. d) (10 pnts) Find the net force acting on the car.

.A 725 N box is being pulled across a level floor. The pulling force is 359 N at an angle of 27.5 degrees above the horizontal. a) (10 pnts.) Draw a Free-Body Diagram for the box. b) (10 pnts.) Find the normal force acting on the box. c) (10 pnts.) If the coefficients of static and kinetic friction are 0.350 and 0.210 respectively, find the net force acting on the box. d) (10 pnts.) How fast will this box accelerate?

4. If a football has a mass of 0.4 kg, and I throw it with a force of 75 Newtons, a. how much will it accelerate when it's in my hand? b. If it's in my hand for 2 seconds, how fast will it be moving when I release it?

An object that weighs 75 N is pulled on a horizontal surface by a horizontal pull of 50 N to the right. The friction force on this object is 30 N to the left What is the acceleration of the object? 1.1 m/s/s 20 m/s/s 0.27 m/s/s 2.6 m/s/s

At the instant a race began, a 57 kg sprinter was found to exert a force of 750 N on the starting block at an angle of 25° angle with respect to the ground. a) Draw a free body diagram. b) Determine the horizontal acceleration of the sprinter? c) If the force was exerted for 0.43 s, with what speed did the sprinter leave the starting block?

Jack feels that his workouts are too easy. He should increase the intensity of his exercise program completely change the type of workout he is doing change his mindset stop exercising because he has reached his fitness goals

You want to hang an object from the ceiling of an elevator that has a maximum acceleration of 4.0 m/s2. b) What TWcombinations of slowing down, speeding up, going up and going down causes the greatest force to be exerted on the fishing line? Moving up and slowing or moving down and slowing moving up and speeding up or moving down and slowing Moving up and speeding up or moving down and speeding up Moving up and slowing or moving down and speeding up.

A 250 gram block is dropped from rest at a height of 1.2m onto a relaxed vertical spring that has a spring constant of k =2.5 N/cm. The block continues downward, compressing the spring until it reaches its lowest point. At the lowest point, how much has the spring been compressed? Please answer in units of meters.

A bullet (m = 0.0250 kg) is fired into a piece of clay (m=4.50 kg). After the impact, the bullet is embedded in the clay, and the combination moves at 0.565 m s' to the South Determine the velocity of the bullet before it hit the clay.

While playing with the Boston Red Sox, Jim Rice swung at a 0.15 kg baseball and accelerated it at a rate of 3.0 x 104 m/s2. How much force did Rice exert on the ball?

Bronco the skydiver falls toward earth. The attraction of the earth on Bronco pulls him down. The reaction to this force is the earth's surface finally pushing against Bronco Bronco finally pushing against the earth's surface Bronco pulling up on the earth None of the above

According to Newton's 3rd Law of Motion, if you push gently on something, it will push on something only under the right conditions gently on you gently on something else on you only if you aren't moving

A car moving at 10.4 m/s crashes into a tree and stops in 0.24 s. The force the seat belt exerts on a passenger in the car to bring the person to a halt is 2,526 N. What is the mass (in kg) of the passenger?

A 20 kg lobster was pulled in the water by several smaller lobsters. If the lobster is moved from rest to a speed of .550 m/s, a distance of 1.55 m. What is the net force applied by the smaller lobsters?

A 0.18 kg softball (let's be real here...it's not soft) moving westward at 20.0 m/s is hit by a bat and brought to a complete stop. What is the change in momentum of the ball after this collision? 3.6 m/s 0.0 kg m/s 3.6 kg m/s westward 3.6 kg m/s eastward 3.6 m/s eastward

A 10 kg block is placed on a table. The area of contact is .04 m². What is the pressure exerted on the table by the block? What is the pressure exerted on the block by the table?

An object of 3 kg on a rough surface inclined at 37 degrees with the horizontal is connected through the pulley to another object of mass m as shown below. The coefficient of kinetic friction is 0.55. Find a) The accelerations of the objects if m=5 kg. ANS b) The mass m for which the 3kg slides down the incline with a constant speed ANS

Aluminum has a density of 2700 kg/m³. A block of aluminum with a volume of 1 m³ is placed into water. a) Does the block sink or float? Explain. b) How much water is displaced? c) If 1 m³ of water has a mass of 1000 kg, find the buoyant force on the block of aluminum. d) How does the buoyant force compare the weight of the aluminum block? Explain.

On a level, frictionless air hockey table, two identical 40g pucks collide. Puck #1 is initially moving along the x-axis at +3.6 m/s (or, 3.6i m/s) and puck #2 is moving along the x-axis at -0.50 m/s. (or, -0.50i m/s). After the collision puck #1 has a velocity given by (0.60i + 1.1j) m/s. a) Find puck #2 's final velocity.

A solid, prefabricated plastic form is lifted by cables. The form can be treated as a massless bar (length 14.0m) with a block of mass in kg as indicated. The center of mass is marked. The cables form are in static equilibrium. Find TL.

Chief Boolie, the jungle dweller, is out hunting for dinner when a coconut falls from a tree and lands on his toe. If the nut fell for 1.4 s, how fast was it traveling when it hit Chief Boolie's toe?

The projectile enters the medium (k = 12.6 x 109 /ms²) and has an acceleration, a = - kx². When t = 0, x = 0 and v = 250 m/s. Determine the distance, x the projectile travels before coming to a complete stop. Treat the projectile as a particle.

An object acted on by three forces moves with constant velocity. One force acting on the object is in the positive a direction and has a magnitude of 6.2 N a second force has a magnitude of 4.4 N and points in the negative y direction. Part B Find the direction of the third force acting on the object.

An object has an acceleration of 12.0 m/s/s. If the mass of this object were reduced to one-third the original value (with no change in its net force), then its new acceleration would be

A football punter accelerates a football from rest to a speed of 15 m/s during the time in which his toe is in contact with the ball (about 0.24 s). If the football has a mass of 0.43 kg, what average force does the punter exert on the ball?

Student X pushes a 10-N box with a force of 2 N. At the same time, Student Y pushes the same box with a force of 6 N, but in the opposite direction. Which would most likely occur? (Ignore friction.) A. The box will move toward Student X. B. The resultant force on the box would be 8 N. C. The box will move toward Student Y. D. The resultant force on the box would be 18 N.

A plane drops a hamper of medical supplies from a height of 4610 m during a practice run over the ocean. The plane's horizontal velocity was 108 m/s at the instant the hamper was dropped. Dalam What is the magnitude of the overall velocity of the hamper at the instant it strikes the surface of the ocean? The acceleration of gravity is 9.8 m/s² Answer in units of m/s.

An arrow leaves a certain bow with a speed of 30 m/s. (a) What is its maximum range? (b) At what angle could the archer point the arrow if it is to reach a target of 70 m awy? A) 92 m, 25 degree B 92 m, 65 degree C both a and b D) none

A 50,000 kg helicopter lifts a 1500 kg crate attached to it by a rope. The helicopter and crate accelerate upward at 0.5 m/s2. (Assume the tension in the rope is constant.) a. What is the weight of the helicopter? b. What is the tension in the rope? c. What is the lift force on the helicopter?

Calculate the net force needed to accelerate a 15.0 kg bag of groceries 2.00m/s² Your answer should have three significant figures.

A car moving along a straight road at 30 m/s slows uniformly to a speed of 10 m/s in a time of 5.0 s. Determine (a) the acceleration of the car and (b) the distance it moves during the third second.

The speed of a train is reduced uniformly from 15 m/s to 7.0 m/s while traveling a distance of 90 m. (a) compute the acceleration. (b) how much farther will the train travel before coming to rest, provided the acceleration remains constant?