"A 60-kg person walks on a 100-kg log at the rate of 0.80 m/s (with respect to the log). With what speed does the log move, with respect to the shore?" O 0.24 m/s O 0.30 m/s O 0.48 m/s O 0.60 m/s

A child riding a bicycle has a total mass of 30.6 kg. The child approaches the top of a hill that is 27.9 m high 27.9 and is 86.8 m (ℓ)  long at 12.1 m/s. If the force of friction between the bicycle and the hill is 26.7 N, what is the child's velocity at the bottom of the hill? (Disregard air resistance, g = 9.8 m/s2.)

True or False? Consider carts colliding on a straight level track.  It is impossible for two identical carts moving at different speeds to collide and stick together and end up not moving.

A block of mass m= 5.00 kg is reased from point A and slides dows the frictionless track shown in the figure. calculate the speed of the block at piont B and C. g= 9.8m/s2

A car weighing 2.5 metric tons and traveling at 90 km/h hits a 500 m long stretch of black ice. Unfortunately, due to skidding, neither accelerating nor braking has any effect on the speed! The driver manages to maintain steady straight direction of motion and the only impact is provided by the ice friction force, which is numerically equal to 4v² Newtons, where the velocity v of the car is measured in m/sec. (a) Using Newton's Second Law F = ma, set up a mathematical model for the position x(t) and velocity v(t) of the car as functions of time t. Start by drawing a diagram and choosing a consistent system of units based on kg, m, sec (1 ton = 1000 kg, 1 m/sec = 3.6 km/h, 1 N = 1 kg · m/sec²). Introduce and label the variables, show the units and write down the differential equations and the intial conditions. (b) Use the model in part a to calculate v(t) and x(t). Fully show the process of solving the initial value problems. (c) Based on your work so far, how long will it take to pass…

Each of the following vectors is given in terms of its xx- and yy-components.

A car of mass 1650 kg, initially at a speed of 70km/h, crushes into a wall, if the accident lasted for 0.2 sec, what is the amount of force exerted in the car during the crash?

k A 13.00 kg particle starts from the origin at time zero. Its velocity as a function of time is given by = 10t² + 1tj where is in meters per second and t is in seconds. (Use the following as necessary: t.) V (a) Find its position as a function of time. ŕ= esc 10/³1 + ²/2 2²; 3 (b) Describe its motion qualitatively. The particle starts from rest at the origin, starts moving in the y direction, and gains speed faster and faster while turning to move more and more nearly parallel to the x axis. Score: 0.06 out of 0.06 Comment: (c) Find its acceleration as a function of time. a = 20ti + lj m/s² (d) Find the net force exerted on the particle as a function of time. F= T= (e) Find the net torque about the origin exerted on the particle as a function of time. N m X X (f) Find the angular momentum of the particle as a function of time. Ľ Need Help? Read It F1 N x (g) Find the kinetic energy of the particle as a function of time. K= x kg m²/s X (h) Find the power injected into the particle as a…

O 0.2 MPa A 3500 Ib. car moving at 25 mi/h is accelerated at a constant rate of 15 ft/s^2^ up to a speed of 50 mi/h. What are the force and total time required? * O 1632 Ibf, 183 s O 7523 Ibf, 175 s O 52500 Ibf, 183 s O 7523 Ibf, 183 s O 1832 Ibf, 175 s O 2083 Ibf, 175 s • Document 14 5jpg O O O OO 0

A 80 kg woman on roller skates pushes a 30 kg girl, also on roller skates, with a force of 100 N. The magnitude of the force exerted by the girl on the woman is O 200 N O 100 N O 50 N O 40 N O 38 N zero