A 41.5-kg person, running horizontally with a velocity of +2.19 m/s, jumps onto a 18.3-kg sled that is initially at rest. (a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. (b) The sled and person coast 30.0 m on level snow before coming to rest. What is the coefficient of kinetic friction between the sled and the snow? (a) Number i (b) Number i Units Units V

A block with mass m1 hangs from a rope that is extended over an ideal pulley and attached to a second block with mass m2 that sits on a ledge slanted at an angle of 20. Suppose the system of blocks is initially held motionless and, when released, begins to accelerate. (a) If m1 = 5.00 kg, m2 = 3.75 kg, and the magnitude of the acceleration of the blocks is 0.140 m/s2, find the magnitude of the kinetic frictional force between the second block and the ledge. ?N. (b) What is the value of the coefficient of kinetic friction between the block and the ledge?

A hockey stick exerts an average force of39 N[S] on a 0.20 kg hockey puck over a displacement of 0.22 m. If the hockey puck started from rest, what is the final velocity of the puck? Assume that the friction between the puck and the ice is negligible.

Lions can run at speeds up to approximately 80.0 km/h. A hungry 109 kg lion running northward at top speed attacks and holds onto a 39.0 kg Thomson's gazelle running eastward at 75.0 km/h. Find the final speed ?fvf of the lion‑gazelle system just after the lion attacks. vf=? in m/s

Most of us know intuitively that in a head-on collision between a large dump truck and a subcompact car, you are better off being in the truck than in the car. Why is this? Many people imagine that the collision force exerted on the car is much greater than that exerted on the truck. To substantiate this view, they point out that the car is crushed, whereas the truck is only dented. This idea of unequal forces, of course, is false; Newton's third law tells us that both objects are acted upon by forces of the same magnitude. The truck suffers less damage because it is made of stronger metal. But what about the two drivers? Do they experience the same forces? To answer this question, suppose that each vehicle is initially moving at 7.70 m/s and that they undergo a perfectly inelastic head-on collision. Each driver has mass 72.0 kg. Including the masses of the drivers, the total masses of the vehicles are 800 kg for the car and 4,000 kg for the truck. If the collision time is 0.110 s,…

A 48.1-kg person, running horizontally with a velocity of +3.23 m/s, jumps onto a 16.8-kg sled that is initially at rest. (a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. (b) The sled and person coast 30.0 m on level snow before coming to rest. What is the coefficient of kinetic friction between the sled and the snow? (a) Number i (b) Number i Save for Later Units Units Attempts: 1 of 3 used Submit Answer

Suppose you are navigating a spacecraft far from other objects. The mass of the spacecraft is 3.2 × 104 kg (about 32 tons). The rocket engines are shut off, and you're coasting along with a constant velocity of km/s. As you pass the location km you briefly fire side thruster rockets, so that your spacecraft experiences a net force of N for 23.0 s. The ejected gases have a mass that is small compared to the mass of the spacecraft. You then continue coasting with the rocket engines turned off. Where are you an hour later? (Think about what approximations or simplifying assumptions you made in your analysis. Also think about the choice of system: what are the surroundings that exert external forces on your system?) 7₁ = m

A 74.6-kg person, running horizontally with a velocity of +4.47 m/s, jumps onto a 11.4-kg sled that is initially at rest. (a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. (b) The sled and person coast 30.0 m on level snow before coming to rest. What is the coefficient of kinetic friction between the sled and the snow? (a) Number i (b) Number i Save for Later Units Units Attempts: 0 of 3 used Submit Answer

You are the juror of a case involving a drunken driver whose 1044.0 kg sports car ran into a stationary 2047.0 kg station wagon stopped at a red traffic light. The cars stuck together and slid with locked wheels for 10.0 m before coming to rest. The coefficient of sliding friction on the dry road was 0.7. Estimate the speed of the sports car when it hit the station wagon. Estimate the instantaneous acceleration of the sports car during the actual collision if the colliding cars reach the same final speed after collapsing a combined total distance of 0.7 m.

A billiard ball strikes and rebounds from the cushion of a pool table perpendicularly. The mass of the ball is 0.38 kg. The ball approaches the cushion with a velocity of +2.30 m/s and rebounds with a velocity of -1.70 m/s. The ball remains in contact with the cushion for a time of 3.40 × 10-3 s. What is the average net force (magnitude and direction) exerted on the ball by the cushion?