2/9
A newly discovered planet has twice the mass and three times the radius of the earth. What is the free-fall acceleration as its surface, in terms of the free-fall acceleration (g) at the surface of the earth?
41 N/m
A force of 30N stretches a spring 0.73 m from equilibrium. What is the value of the spring constant?
41 N/m
A spring originally 2.10 m long. A force of 30 N stretches a spring to a new length of 2.83 m. What is the value of the spring constant?
4.4 m
An irregularly shaped object 10m long is placed with each end on a scale. If the scale on the right reads 74N and the scale on the left reads 93N, how far from the left is the center of gravity?
4.8 seconds
a 23kg mass is connected to a nail on a frictionless table by a (massless) string of length 1.3m. If the tension in the string is 51N while the mass moves in a uniform circle on the table, how long does it take for the mass to make one complete revolution?
24 rad
A wheel accelerates from rest to 59 rad/s2 at a rate of 74 rad/s2. Through what angle (radians) did the wheel turn while accelerating?
4.0*10^16 kg
Spaceman Speff orbits planet X with his spaceship. To remain in orbit at 421km from the plaent’s center, he should maintain a speed of 80 m/s. What is the mass of planet X?
4.0*10^19 kg
Spaceman Speff orbits planet X with his spaceship. To remain in orbit at 421 km from the planet’s center, he should maintain a speed of 80 m/s. What is the mass of planet X? G= 6.67*10^11
5707 m/s^2
An electrical motor spins at a constant speed 269.5 rpm. If the armature radius is 7.165 cm, what is the acceleration of the edge of the rotor?
4.6m/s
A child sitting on the outer edge of the merry go round that is 18m in diameter. If the merry go round makes 4.9 rev/min what is the velocity of the child in m/s?
G=5.8*10^-8 N
What is the gravitational force acting on a person due to another person standing 2 meters away? Assume each person is 59 kg. G=6.67*10^11 N8m^2/kg^2
greater the farther the mass is from the center
A small mass is placed on a record turntable that is rotating at a constant 45rpm. The acceleration of the mass is
true
True or False: If the forces on an object balance, it does not necessarily follow that the torques balance
false
True or False: A car is being towed at a constant velocity on a horizontal road using a horizontal chain. The tension in the chain must be equal to the weight on the car in order to maintain constant velocity
independent (in magnitude) of the position of the mass on the turntable
A small mass of clay is placed on a turntable that is rotating at a constant 45 rpm. The angular velocity ohmega of the clay mass is
False
True of False: Earth’s gravity is caused by our planet’s spin on its axis
False
True of False: Astronauts orbiting satellites are weightless because they are so far from Earth that the gravitational pull is too weak to feel
false
True or False: If two objects have the same moment of inertia, they must have the same mass
D
Which of these objects is in state equilibrium?
20kg
An 80 kg man balances the boy on the teeter totter. What is the approximate mass of the boy?
1 meter
A 40kg, 5m long beam is supported by, but not attached to, the two posts as shown below. A 20kg boy starts walking along the beam. How close can he get to the right end of the beam without tipping it?
Fd
five equal forces are applied to a door. Which force creates the largest negative torque about the hinge?
1kg
A 1kg rock is suspended by a massless string from one end of a 1m measuring stick. What is the weight of the measuring stick if it is balanced by a support force at teh 0.25m mark?
the steel end is heavier
A hammer is balanced on a fingertip, showing the location of the center of gravity. Suppose the hammer is cut in half directly able to finger tip at the center of gravity. Which piece would weigh more?
the hoop
Consider the following four objects: a hoop, solid sphere, flat disk, hollow sphere. Each of the objects has mass M and radius R. The axis of rotation passes through the center of each object, and is perpendicular to the plane of the hoop and the plane of the flat disk. Which object requires the largest torque to give it the same angular acceleration?
E, since the vector is pointing to the center of the circle (curved path)
As seen from above, a car rounds a curved path (blue line) as show at a constant speed. Which vector best represents the net force acting on the car?
1.6 N
The 2.0kg, 30cm disk shown below is spinning at 300 rpm (31.4rad/sec). How much friction force must the brake apply to the rim to bring the disk to a stop in 3.0 seconds?
17 kg
A torque of 12 N*m is applied to a solid, uniform disk of radius 0.50m. If the disk accelerates as 5.7 rad/s2, what is the mass of the disk?
false
True or False: there must be equal amounts of mass on either side of the center of gravity, for every object
