Physics Force & Laws Of Motion Level: High School
Friction
A horizontal contact force accelerates a block of mass 1.10 kg from 10.0 m/s on a rough , horizontal surface .a) If the coefficient of kinetic friction between the block and the surface is 0.190 , and the block travels 12.0 m while accelerating, what is the magnitude of the contact force ?
b) What is the average rate at which friction takes energy away from the block ?
Physics Force & Laws Of Motion Level: High School
Impulse
A 0.15-kg baseball is thrown with a speed of 20 m/s . It is hit straight back at the pitcher with a final speed of 25 m/s .a) What is the impulse delivered to the ball ?
b) Find the average force exerted by the bat on the ball if the two are in contact for 0.002 s .
Physics Force & Laws Of Motion Level: High School
Newton’s Law of Motion
In the figure which is shown at “click here” , the coefficient of kinetic friction between the surface and the larger block is 0.20 and the coefficient of kinetic friction between the surface and the smaller block is 0.30 . If F = 10 N and M = 1.0 kg , what is the tension in the connecting string ? Draw free body diagram for each block and apply Newton’s law of motion to solve .
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
At time t = 2.3 s , a 4 kg block that initially moves with a constant speed of 6 m/s undergoes an inelastic collision with another block . Any two inertial observations must agree that .a) The event took place at t = 2.3 s .
b) The initial speed of the block is 6 m/s .
c) The initial speed of the block has magnitude 24 kg*m/s .
d) The second block is moving after the collision .
e) The momentum of the two block system is conserved during the collision .
Physics Force & Laws Of Motion Level: High School
Pulley Having Mass
A 15.0 kg object and a 10.0 kg object are suspended joined by a cord that passes over a pulley with a radius of 10.0 cm and a mass of 3.00 kg . The cord has a negligible mass and does not slip on the pulley . The pulley rotates on its axis without friction . The objects start from rest 3.00 m apart . Treat the pulley as a uniform disk , and determine the speeds of the two objects as they pass each other .
Physics Force & Laws Of Motion Level: High School
Conservation of Linear Momentum
In which one of the following situation is linear momentum not conserved ?a) A bomb suspended by a string explodes into one hundred fragments.
b) A bowling ball collides with ten pins.
c) A golf ball is struck by a club.
d) An astronaut floating in space throws a hammer away and subsequently moves in the opposite direction.
e) A tree limb is struck by lightning and falls to the ground .
e) A tree limb is struck by lightning and falls to the ground .
Physics Force & Laws Of Motion Level: High School
Friction
The two blocks are connected by a light string that passes over a frictionless pulley with a negligible mass . The 3 kg block lies on a rough horizontal surface with a constant coefficient of kinetic friction 0.1 . The hanging block has a mass of 6 kg. The system starts from rest . The acceleration of gravity is 9.8 m/s2 . What is the speed of the 6 kg hanging mass when it has fallen a height 9 m ? Answer in units of m/s .
Physics Force & Laws Of Motion Level: High School
Conservation of momentum
Sally skywalker is outside the spaceship repairing some hardware , when her safety line to the spaceship mysteriously break . Her thruster pack is also damaged , so she has no obvious means of propulsion . She is at rest relative to the spaceship , 267 m away from it , with only 3 minutes of oxygen left in her life support pack . To get back to the ship , she decided to remove her tool kit . and throw it away . Assuming that the combined mass of the Sallly and the spacecraft is 113 kg and the mass of the tool kit is 9 kg , what is the minimum speed (in m/s) that she can throw the tool kit , in order to get back to the spaceship before her oxygen supply is exhausted ?a) 9.9
b) 11.6
c) 13.6
d) 15.9
e) 18.6
Physics Force & Laws Of Motion Level: High School
Friction
A large block of mass M = 7.3 kg is on top of a rough table and is connected by a massless string over a pulley to a smaller hanging mass m = 2.8 kg as shown in the figure at “click here” . what is the minimum coefficient of static friction on the surface of the table such that the system remains at rest and does not slip ?a) 0.163
b) 0.217
c) 0.288
d) 0.384
e) .0510
Physics Force & Laws Of Motion Level: High School
Tension in a String
An object of mass m is hanging by a string from the roof of an elevator . The elevator may or may not be in motion . depending on the statements below . You are asked to determine the magnitude of the tension in the string . Which of the following statement is/are true ?a) If the elevator is moving up with increasing speed , the tension is less than mg .
b) If the elevator is at rest , the tension is less than mg .
c) If the elevator is moving up with decreasing speed , the tension is greater than mg .
d) If the elevator is in free fall ,the tension is zero .
Physics Force & Laws Of Motion Level: High School
Momentum
The momentum of a particle is proportional to the square of its velocity .True
False
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
A plane flying horizontally , released a bomb , which explodes before hitting the ground . Neglecting air resistance , the centre of mass of the bomb fragments , just after the explosion is ?Zero
Moves horizontally
Moves along a parabolic path
Moves vertically
Physics Force & Laws Of Motion Level: High School
Conservation of Linear Momentum
In an inelastic collision the final total momentum is ?The same as the initial momentum
None of these
Less than the initial momentum
More than the initial momentum
Physics Force & Laws Of Motion Level: High School
Inelastic Collision
A 3 kg ball of putty is moving at 1 m/s collides and stick to a 2 kg ball initially at rest . The putty and the ball then move with a momentum of ?3 N s
0 N s
2 N s
1 N s
4 N s
Physics Force & Laws Of Motion Level: High School
Two cars suffers a head on collision . What is conserved in the collision ?Momentum
Kinetic energy
Mechanical energy and momentum
None of the above