The re-creation of an event by comparing two situations in which all the factors are identical except one is called a?
A tentative scientific explanation which may or may not be rejected upon further experimentation is called a?
If you double the mass of an object while an unbalanced force remains constant?
the acceleration of the object is halved
When you roll a ball across the floor, it comes to a stop because you are no longer exerting a force on it? (True or false)
The tendency of a moving object to remain in unchanging motion in the absence of an unbalanced force is called?
A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the stone when it is halfway to the top of its path is about?
A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the brakes were applied was?
A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?
A baseball player bats a ball with a force of 1000 N. The reaction force that the ball exerts against the bat is?
A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s?
An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is on Earth. In the first 5 seconds it falls a distance of?
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by?
both the same
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is?
10 times as much force as the force on the 1-kg book
A ball is thrown upwards and returns to the same position. Compared with its original speed after release, its speed when it returns is about?
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface?
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is?
A large and a small person wish to parachute at equal terminal velocities. The larger person will have to?
get a larger parachute
A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass?
the one on the moon
If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity?
the object eventually slides to a stop
Suppose you slowly, and at constant speed, lift a book weighing 12 N from the floor to a shelf 2 m above the floor. Neglect air resistance. While you are lifting, the net force on the book is?
A 10-N block and a 1-N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we would have to push with?
10 times as much force on the heavier block
A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is?
the same for both
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the?
force the glove exerts on the ball
An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The magnitude of the resultant force on the object is?
The human body can, under certain conditions, withstand an acceleration of 10 g. What net force would produce this acceleration of a 50-kg person?
Two billiards balls, each of mass m, move towards each other at same speeds, v and collide head on. Their combined momentum after the collision is?
A 2000 N car travels 50 m along a level road, powered by a drive force of 1000 N. The work done by the drive force is?
In its monthly bill, the electric company charges you primarily for?
the electric energy you consume every month
In order for you to get out of bed with the least amount of work, would it be better for your bed to be on the floor or a meter high?
It would be better for the bed to be a meter high, because then you would not need to do as much work in lifting yourself to your feet.
Nearly all of the energy consumed today is provided by petroleum, coal, hydropower and nuclear sources. (true or false)
Two students stand poised to leap off a high dive structure into the swimming pool below. Student B is twice as massive as student A. Which of the following is true?
student B did twice as much work climbing to the top of the structure
Which of the following energy transformations represents the operation of a wind turbine [a device that uses the wind as an energy resource]?
Kin E leads to Electric E
Difference between speed and velocity
relates to vectors and arrows.
same lengths=same speeds
different directions=different velocities
Newton's first law of motion
If no external forces act on a moving object, then its
motion will continue on without changing.
Newton's second law of motion
If a force F is applied to an object of mass m, the
object experiences a nonzero acceleration a in the
direction of the applied
Why do things accelerate?
Objects will continue to move in the same direction and at a constant speed unless a force is applied
Newton's third law of motion
For every applied force, there also occurs a force of equal magnitude acting in the opposite direction at precisely the same point.