Suppose a car approaches a hill and has an initial speed of

106

k

m

/

h

at the bottom of the hill. The driver takes her foot off the gas pedal and allows the car to coast up the hill.

A. If in actuality a

780

k

g

car with an initial speed of

106

k

m

/

h

is observed to coast up a hill and stops at a height

21.5

m

above its starting point, how much thermal energy was generated by friction in

J

?

B. What is the magnitude of the average force in newtons of friction if the hill has a slope of

27

∘

above the horizontal.

Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? velocity acceleration equilibrium force inertia

3. a worker pushes a 30.5 kg polished stone along a polished table with a force on bonin a straight line for 5.20 s after starting from rest. there is no friction between thestone and the table. at the end of the table. the stone is hooked to a cable with a lengthof 62.0 cm to rotate it to a rough table to store until they can be picked up. the roughtable has a coefficient of static friction 0.702 with the polished stone. remember that 8= 9.80 m/s2a) what is the speed of the stone when it is hooked to the cable? b) what is the tension in the cable while the stone is rotating? (there is still nofriction)c) how much force is needed to make the stone begin sliding from rest on therough table? ius = 0.70262.0 cm30.5 kg20.5 kg6= 0

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?