Physics Vectors Level: High School
Which of these quantities must be a scalar ?a. kinetic energy .
b. force .
c. velocity .
d. linear momentum .
e. acceleration .
Physics Force & Laws Of Motion Level: High School
(A) A 81.6 kg person throws a 0.068 kg snowball forward with a ground speed of 13.9 m/s . A second person , of mass 64.8 kg catches the snowball . Both people are on skates . The first person is initially moving forward with a speed of 3.17 m/s , and the second person is initially at rest . What is the velocity of the first person immediately after the snowball is thrown ? Disregard friction between the skates and the ice , Answer in units of m/s .(B)What is the velocity of the second person immediately after the snowball is caught ?
Physics Force & Laws Of Motion Level: High School
Conservation of Linear momentum
A)A rifle with a weight of 21 N fires a 7.9 g bullet with a speed of 161 m/s . The acceleration of gravity is 9.81 m/s^2. Find the recoil speed of the rifle . answer in units of m/s .A) If a 566 N man holds the rifle firmly against his shoulder , find the recoil speed of man and rifle
Physics Kinematics Level: High School
A 1 kg wood block is pressed against a vetical wood wall by 12 N of force 30^ above the horizontal . If the block is intially at rest , will it move upward or stay at rest ? ( Coefficient of static friction on wood is 0.5 )
Physics Kinematics Level: High School
An archer standing on a 15^ slope arrow 20^ above the horizontal . How far down the sope does the arrow hit if it is shot with a speed of 50 m/s from 1.75 m above ground ?
Physics Force & Laws Of Motion Level: High School
Demonstrate the Newton’s third law is true by taking an example from real life . Then explain how Newton’s third law applies in those situations .
Physics Force & Laws Of Motion Level: High School
In the ideal apparatus shown in the diagram, at “click here” , m1 = 2.0 kg . What is m2 if both masses are rest ? How about if both masses are moving at constant velocity ?
Physics Force & Laws Of Motion Level: High School
The Atwood machine consists of two masses suspended from a fixed pulley . It is named after British scientist George Atwood (1746-1807) , who used it to study motion and to measure the value of g. If m1 = 0.55 kg and m2 = 0.80 kg ,(a) What is the acceleration of the system
(b) What is the magnitude of the tension in the string
Physics Force & Laws Of Motion Level: High School
A boy pulls box of mass 30 kg with a force of 25 N in the direction shown in the figure at “click here”.(a) Ignoring friction of the box , what is the acceleration of the box ?
(b) What is the normal force exerted on the box by the ground ?
Physics Force & Laws Of Motion Level: High School
Jane and John , with masses if 50 kg and 60 kg , respectively , stand on a frictionless surface 10 m apart . John pulls on a rope that connects him to Jane , giving Jane an acceleration of 0.92 m/s^2 . At what rate will John accelerate ? What is the direction of his acceleration ?
Physics Force & Laws Of Motion Level: High School
“Newton’s second law also explains why all objects in free fall have the same acceleration . “Do you agree with this statement ? Why ? or why not ?
Physics Force & Laws Of Motion Level: High School
In an emergency stop to avoid an accident , a shoulder -strap seat belt holds a 60-kg passenger firmly in place . If the car were initially traveling at 90 km/h and came to a stop in 5.5 s along a straight , level road , what was the average force applied to the passenger by the seatbelt ?
Physics Force & Laws Of Motion Level: High School
In a college homecoming competition , 16 students lift a sports car . While holding the car off the ground, each student exerts an upward force of 400 N .(a) What is the mass of the car in kilograms
(b) What is the weight in pounds ?
Physics Force & Laws Of Motion Level: High School
A 1.5 kg object moves up the y-axis at a constant speed . when it reaches the origin, the forces F1 = 5.0 N at 37 degree above the +x-axis, F2 = 2.5 N in the +x-direction, F3 = 3.5 N at 45 degree below the –x-axis , and F4 = 1.5 N in the –y direction are applied to it .(a) Will the object continue to move along the y-axis ?
(b) If not , what simultaneously applied force will keep it moving along the y-axis at a constant speed ?
Physics Rotational Mechanics Level: High School
Center of mass
Two people , one of mass 77.0 kg and other of mass 60.6 kg, sit in rowboat of mass 83.8 kg . With the boat initially at rest , the two people , who have been sitting at opposite ends of the boat 2.00 m apart from each other , now exchange seats , How far will the boat move ?