Exam 4 Flashcards
(20 cards)
The reason the moon does not crash into the Earth is that the
moon has sufficient tangential speed
The planet Jupiter is about 300 time as massive as Earth, yet on its surface you would weight only about 3 times as much because
Jupiter’s radius is about 10 times Earth’s radius
A dump truck has a large cubical concrete block in its bed. The coefficients of friction between this block and the floor if the bed are uk = 0.450 and us = 0.650. As the bed is slowly tilted above the horizontal, will the brick first begin to slide or will it first tip over?
it will first begin to slide
The angular momentum of a system remains constant
when zero net torque acts on the system
A torque of 12Nm applied to a solid, uniform disk of radius 0.50m, causing the disk to accelerate at 5.7 rad/s^2. What is the mass of the disk? (I for disk is 1/2 Mr^2)
I=T/a
T/a = (1/2)Mr^2
solve for m
If the torque on an object adds up to zero______
the object could be both turning and accelerating linearly
A nonuniform, 80.0g meterstick balances when the support is placed as the 51.0-cm mark. At what location on the meterstick should a 5.00g tack be policed so that the stick will balance at the 50.0cm mark?
Tcw = Tacw
80g(51cm-50cm) = 5g(50cn - x)
*solve for x
The reason an astronaut in an earth satellite feels weightless is that
the astronaut is falling
A 95N force exerted at the end of a 0.50m long torque wrench gives rise to a torque of 15 Nm. What is the angle between the wrench handle and the direction of the applied force?
T = F L sin(theta) sin(theta) = T/F L
Planet Z-34 has a mass equal to 1/3 that of earth, a radius equal to 1/3 that of earth, and an axial spin rate 1/2 that of Earth. With g representing, as usual, the acceleration due to gravity on the surface of Earth, the acceleration due to gravity on the surface of Z-34 is
3g
Two objects move toward each other due to gravity. As the objects get closer and closer, the force between them ____
increases
In comparison with other fundamental forces, the universal gravitational constant G indicates that gravity is
very weak
A satellite is orbiting earth. If a payload of material is added until it doubles the satellite’s mass, the earth’s pull of gravity on this satellite will double but the satellite’s orbit will not be affected.
true
A tire is rolling along a road, without slipping, with a velocity v. A piece of tape is attached to the tire. When the tape is opposite the road (at the top of the tire), its velocity with respect to the road is
2v
A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radii and are of uniform density. If the three are released simultaneously, at the top of an inclined plane and roll without slipping, which one will reach the bottom first?
solid sphere
A baseball is located at the surface of the earth. Which statements about it are correct?
The gravitational force on the ball due to the earth is exactly the same as the gravitational force on the earth due to the ball.
Fg
Gm1m2/r^2
U
-GmEm/r
series T
I (alpha)
alpha
a/r
