A dog (19 kgkg ) is running with a speed of 4.1 m/sm/s . What is the force required to stop the dog? Assume that the force is horizontal, constant, and is applied over a distance of 0.55 mm .
A 44.0 kgkg parachutist is moving straight downward with a speed of 3.90 m/s If the parachutist comes to rest with constant acceleration over a distance of 0.850 mm , what force does the ground exert on her? If the parachutist comes to rest over a shorter distance, is the force exerted by the ground greater than, less than, or the same as in part A? Explain..
Zach, whose mass is 79 kgkg , is in an elevator descending at 9 m/sm/s . The elevator takes 2.6 ss to brake to a stop, with a constant acceleration, at the first floor.What is the force the elevator exerts on Zach while the elevator is braking?
Jack (mass 54.0 kgkg) is sliding due east with speed 8.00 m/sm/s on the surface of a frozen pond. He collides with Jill (mass 46.0 kgkg), who is initially at rest. After the collision, Jack is traveling at 5.00 m/sm/s in a direction 34.0∘∘ north of east. Ignore friction. What is the direction of the Jill's velocity after the collision? What is the magnitude of the Jill's velocity after the collision?
A 1400 kgkg car traveling at a speed of 20 m/sm/s skids to a halt on wet concrete where μkμkmu_k = 0.60. how long are the skid marks?
Problem 1 A dog starts running at a constant speed v0= 6 m/s. Initially, the dog is at a distance d= 10 m from a window. The window is located at a height h= 20 m above the ground. On top of the window there is a plant pot of mass m = 3 kg. The pot falls from the window 2 seconds after the dog starts running. a) What is the speed (inm/s2) of the pot when it reaches...
At t=1.0st=1.0s, a 0.42 kgkg object is falling with a speed of 6.5 m/sm/s. At t=2.0st=2.0s, it has a kinetic energy of 38 J What is the kinetic energy of the object at t=1.0st=1.0s? Express your answer using two significant figures. What is the speed of the object at t=2.0st=2.0s? Express your answer using two significant figures.
You are asked to design a spring that will give a 1150 kgkg satellite a speed of 3.05 m/sm/s relative to an orbiting space shuttle. Your spring is to give the satellite a maximum acceleration of 5.00g5.00g. The spring's mass, the recoil kinetic energy of the shuttle, and changes in gravitational potential energy will all be negligible. Part a) What must the force constant of the spring be? Take the free fall acceleration to be g = 9.80 m/s2 part...
A dog chases a mailman with a speed of 6 m/s. If the dog barks with a frequency of 415 Hz, what frequency does the mailman here as he is running away from the dog with a speed of 12 m/s?
A bullet with a mass of 4.2 gg and a speed of 650 m/sm/s is fired at a block of wood with a mass of 9.8×10−2 kgkg . The block rests on a frictionless surface, and is thin enough that the bullet passes completely through it. Immediately after the bullet exits the block, the speed of the block is 22 m/sm/s . What is the speed of the bullet when it exits the block? Is the final kinetic energy of...
What is the kinetic energy of a 30 kg dog that is running at a speed of 7.8 m/s (about 17 mi/h)?