let me see that (free) body (diagram)!
hockey puck on smooth ice
gravitational force in the negative y-direction, normal force in the positive y-direction
four forces, F1 = 523N east, F2= 200N north, F3= 888N west and F4=120N south, act on a 4.44kg object. this is the magnitude of the net force of the object.
374N
a 90.72kg sumo wrestler slams into a 34kg middle schooler, causing the middle schooler to fly wayyyy back on collision. is the force applied by the sumo wrestler on the middle schooler greater than, equal to, lesser than, or indiscernible (due to lack of information) compared to the force the middle schooler applies on the sumo wrestler?
the forces are exactly equal to each other
this is newton's second law when an object is moving at constant velocity
f=m(0)
this force causes car tires to go along a curved road
frictional force
a soccer player slide tackling to the left, on an inclined turf field.
a correct FBD would have a normal force vector, gravitational force vector and a static frictional force vector. these vectors would align perpendicularly with the incline in the + y-axis, straight down, and along the negative x-axis, respectively.
let Fapplied = 350N, θ = 25°, and the mass of a backpack with books in it be m=6.95kg. based on these conditions, this is the acceleration of the backpack in m/s2.
45.64 m/s2
you are pushing 3 guinea pigs that are sat side-by-side with a force R of about 10N. the guinea pig you are actively applying force to (g1) weighs 0.9kg, with the one directly to its left (g2) weighing 1.27kg, and the one next to that one (g3) weighing 2.27kg. this is the acceleration of the guinea pigs on a frictionless surface.
2.25 m/s2
this is the derived acceleration of a system on an atwood machine.
a =(m2-m1/m1+m2)(g)
a m1 of 1kg is tied to m2 of 2kg, which has a force F pulling the system towards the right. what would be the applied force of magnitude for the tension in the string between the masses?
1/3 F
a dog-sled system being pulled straight forward on a rough horizontal path, by a child holding a string 20° above the horizontal.
normal force in the (+) y-direction, gravitational force in the (-) y-direction, frictional force in the (-) x-direction and the tension force in the (+) x-direction, 20° above the x-axis
an Atwood machine (with negligible mass) has a 9.2kg mass hanging from the left called m1 and a 6.7kg hanging from the right called m2. this is the magnitude of acceleration for m1.
1.57 m/s2
a homeowner pushes a lawn mower across a horizontal patch of grass with a constant speed by applying a force P. The arrows in the diagram shown correctly indicate the directions but not the magnitudes of the various forces on the lawn mower. which of the following relations among the various forces magnitudes, W, f, N, P is correct; P > f and N >W; P < f and N = W; P > f and N < W; P = f and N > W
P > f and N >W; the downward angle of P increases normal force and P has a component of its vector that balances the frictional force making it larger than f
two masses, m1 and m2, are connected by a cord and arranged such that m1 is sliding on a horizontal frictionless surface and m2 is hanging from a light frictionless pulley. What would be the mass of the falling mass m2, if both m1 and the tension, T, I the cord were known?
Tm1/(gm1 - T)
s1, a satellite orbiting around Earth exerts a force H on Earth. s2, a satellite about twice the distance away also orbits Earth, exerting a force J on Earth. what is the difference between forces H and J and forces H1 and force J1, the gravitational pull Earth exterts on both s1 and s2?
no difference, they should be 3rd law pairs.
you, right before you fall off the railing at top golf because your friend pushed you >:(
(standard Cartesian coords) gravitational force in the (-) y-direction, normal force in the (+) y-direction from the platform on you, friction in the (-) x-direction that was supposed to prevent this with the additional applied force of the push your friend gave you.
when an object of weight W is suspended from the center of a massless string as shown in the diagram, the tension at any point in the string is
2Tcosθ - W or W/(2cosθ)
a helicopter holding a 70kg package suspended from a rope 5m long accelerates upward at a rate of 5.2 m/s2. neglect air resistance on the package. determine the tension in the rope.
1050N
a ball of mass m is suspended from two strings of unequal length as shown above. the magnitudes of the tensions T1 and T2 in the strings must satisfy which of the following relations: T1 = T2, T1 > T2, T1 < T2, T1 + T2 = mg?
T1 < T2 (since T2 is more vertical, it is supporting more weight of the ball; the horizontal components of both tensions are equal though)
A ball falls straight down through the air under the influence of gravity. There is a force X on the ball opposing the ball's motion with magnitude given by F = bv, in which v is the speed of the ball and b is a positive constant. The ball reaches a terminal velocity after a time t. Is the magnitude of the acceleration at time t/2 increasing, decreasing, 10 m/s/s, or zero?
decreasing
a person sitting on a platform attached to a rope.
same tension force for both the platform and the person, except the tension force on the person is in the (+) y-direction while the platform's tension force is in the (-) y-direction. gravitational force on both, with the Fg on the person in the (-) y-direction and Fg on the platform in the (+) y-direction. the normal force on the platform from the person is also added to the gravitational force, while the normal force of the platform on the person added to the tension force.
a block of mass 3kg, initially at rest, is pulled along a frictionless horizontal surface with a force shown as a function of time t by the graph above. the acceleration of the block at t = 2s is
4/3 m/s2
the same helicopter from another question, which is holding a 70kg package suspended from a 5m long rope, accelerates upward at a rate of 5.2m/s2, has now cut the rope the package was hanging off of. determine the distance between the package and the helicopter 2.0 seconds after the rope is cut.
35m
a rope of negligible mass passes over a pulley of negligible mass attached to the ceiling, as shown in the diagram. one end of the rope is held by Student A of mass 70kg, who is at rest on the floor. the opposite end of the rope is held by Student B of mass 60kg, who is suspended at rest above the floor. Use g = 10 m/s2. calculate the force exerted by the floor on Student A.
100N (tension in the rope is equal to the weight of student B, use this as T in your sum of forces for student A)
a 6kg block initially at rest is pushed against a wall by a 100N force as shown. the coefficient of kinetic friction is 0.30 while the coefficient of static friction is 0.50. what is true of the kinetic friction acting on the block after a time of 1 second?
kinetic friction acts downward on the block