By driving west 6 blocks from the starting point
A person drives north 6 blocks, then turns west, and drives 6 blocks. The driver then turns south and drives 6 blocks. How could the driver have made the distance shorter wile maintaining the same displacement?
What is the velocity of a bobsled whose displacement-time graph indicates that it traveled 100m in 25s?
A displacement-time graph indicates that an object moves 100m in 4s and then remains at rest for 6s. Whats is the average velocity of the object?
a ball moving at a constant speed around a circular track
Which example identifies a change in motion that produces acceleration?
An object moving at 30 m/s takes 5s to come to a stop. What is the object's acceleration?
linear, sloping downward
A velocity-time graph shows that a car moves at 10 m/s for 10 s. The car's speed then steadily decreases until it comes to a stop at 30 s. Which of the following describes the slope of the speed-time graph from 10 s to 30 s?
the orange's inertia
An orange might roll off your cafeteria tray when you stop suddenly because of what?
If a force of 12 N is applied to an object with a mass of 2 kg, the object will accelerate at...?
when a tennis rackets strikes a tennis ball, when stepping from a curb, when rowing a boat
In which of the following are action and reaction forces involved?
What is the momentum of a 50-kilogram ice skater gliding across the ice at a speed of 5 m/s?
Acts as an unbalanced force on the satellite, and changes the direction of the satellite
The centripetal force acting on a satellite in orbit..?
A small 20-kilogram canoe is floating downriver at a speed of 2 m/s. What is the canoe's kinetic energy?
A 13-kg sled is moving at a speed of 3.0 m/s. At which of the following speeds will the sled have twice as much kinetic energy?
An object's gravitational potential energy is NOT directly related to which of the following?
The objects acceleration due to gravity is less on the moon
Why is the gravitational potential energy of an object 1 meter above the moon's surface less than its potential energy 1 meter above Earth's surface?
A 4-kilogram cat is resting on top of a bookshelf that is 3 meters high. What is the cat's gravitational potential energy relative to the floor if the acceleration due to gravity is 9.8 m/s2?
Reference level from which the height is measured
The gravitational potential energy of an object is always measured relative to the..?
Energy can be created or destroyed and energy can be transformed from one form to another.
True or False
chemical to thermal to mechanical
Which of the following describes the energy transformations in a car's engine?
work is done in climbing stairs, lifting a book and pushing a shopping cart..so none of the above.
In which of the following is no work done?
A and C (first and middle)
The kinetic energy of the pendulum bob in Figure 15-1 increases the most between locations..?
the force is not in the direction of the object's motion
A force acting on an object does no work if..?
If you perform 40 joules of work lifting a 10-N box from the floor to a shelf, how high is the shelf?
If you exert a force of 700 N to walk 6 m up a flight of stairs in 6 s, how much power do you use?
To increase power, you can increase the amount of work you do in a given amount of time, or you can do a given amount of work in less time.
True or False?
increase a force and increase the distance a force moves an object
When a machine does work, it cannot do which of the following?
less than the ideal mechanical advantage of the machine
The actual mechanical advantage of a machine is?
ideal mechanical advantage
If you know the input distance and output distance of a machine, which of the following can you calculate?
A 120-m long ski lift carries skiers from a station at the foot of a slope to a second station 40 m above. What is the IMA of the lift?
If you have to apply 40 N of force on a crowbar to lift a rock that weights 400 N, what is the actual mechanical advantage of the crowbar?
some work input is lost to friction
The efficiency of a machine is always less than 100 percent because..?
A mechanical device requires 420 J of work to do 230 J of work in lifting a crate. What is the efficiency of the device?
A motor with an efficiency of 75 percent must supply 240 J of useful work. What amount of work must be supplied to the motor?
increasing the distance through which the force is applied
An inclined plane reduces the effort force by..?
number of rope segments supporting the load
The ideal mechanical advantage of a pulley system is equal to the
dividing the radius of the wheel by the radius of the axle
The ideal mechanical advantage of a wheel and axle is found by
is made up of town or more simple machines that operate together
A machine is classified as a compound machine if it
Heat is the transfer of thermal energy from one object to another because of a difference in
What property of an object is related to the average kinetic energy of the particles in that object?
Q=0.75g' 0.385J/gC' 22C
The specific heat of copper is 0.385 J/g·°C. Which equation would you use to calculate the amount of heat needed to raise the temperature of 0.75 g of copper from 7°C to 29°C?
Convection and Conduction
The vacuum inside the thermos bottle shown in Figure 16-1 stops which type of thermal energy transfer to keep the liquid hot?
The direction and length of a straight line from the starting point to the ending point of an object's motion is _______________.
The difference between speed and velocity is that velocity indicates the ___________ of motion and speed does not.
A displacement-time graph indicates an object moves 20 km in 4 h. The average velocity of the object is ________ km/h.
Because its _________ is always changing, an object moving in a circular path experiences a continuous change in velocity.
The velocity of an object moving in a straight line changes at a constant rate when the object is experiencing constant _______.
Can the size of an object's displacement ever be greater than the distance the object travels?
Can the size of an object's displacement ever be less than the distance the object travels?
If the speedometer on a car indicates a constant speed, can you be sure the car is not accelerating?
The force that opposes the motion of objects that touch as they move past each other is called _________.
It usually takes more force to start an object sliding than it does to keep an object sliding because static friction is usually __________ than sliding friction.
During a head-on auto collision, ___________ causes a passenger in the front seat to continue moving _______.
The acceleration of an object is equal to the net ________ acting on the object divided by the object's ________.
If a golf ball and bowling ball are rolling at the same speed, the ______ ball has greater momentum
In a closed system, the loss of momentum of one object _______ the gain in momentum of another object.
The sum of the kinetic energy and potential energy of an object is called its _________energy.
conservation of energy
"Energy cannot be created or destroyed" is a statement of the law of ______________.
When an apple falls from a tree to the ground, the apple's beginning kinetic energy and ending gravitational potential energy are both equal to __________.
A & E
In Figure 15-1, the gravitational potential energy of the pendulum bob is largest at locations ______.