A 52.1-kg person, running horizontally with a velocity of +4.62 m/s, jumps onto a 14.7-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?

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

8.9 · A 0.160-kg hockey puck is moving on an icy, frictionless, horizontal surface. At t = 0, the puck is moving to the right at 3.00 m/s. (a) Calculate the velocity of the puck (magnitude and direction) after a force of 25.0N directed to the right has been applied for 0.050 s. (b) If, instead, a force of 12.0 N directed to the left is applied from 1 = 0 to t = 0.050 s, what is the final velocity of the puck?

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 1150 kg automobile is at rest at a traffic signal. At the instant the light turns green, the automobile starts to move with a constant acceleration of 5.6 m/s?. At the same instant a 2250 kg truck, traveling at a constant speed of 8.4 m/s, overtakes and passes the automobile. (a) How far is the center of mass of the automobile- truck system from the traffic light at t = 3.7 s? (b) What is the speed of the center of mass of the automobile- truck system then? (a) Number i Unit (b) Number i Unit

A small block of mass m, - 0.755 kg is released from rest at the top of a curved wedge of mass m, = 3.50 kg, which sits on a frictionless horizontal surface as in figure (a). When the block leaves the wedge, its velocity is measured to be 4.00 m/s to the right, as in figure (b). m2 4.00 m/s (a) What is the velocity of the wedge after the block reaches the horizontal surface? (Enter the magnitude of the velocity.) m/s (b) What is the height h of the wedge?

A 90.0 kg fullback running 36.9° north of east with a speed of 5.00 m/s is tackled and held onto by an 60.4 kg opponent running north with a speed of 5.34 m/s. What is the magnitude of the velocity of the players immediately after the tackle?