Newton's Laws
The force required to accelerate a 2.0-kilogram mass at 4.0 meters per second2 is ______
8 N
Compared to the force needed to start sliding a crate across a rough level floor, the force needed to keep it sliding once it is moving is ________.
less
A 65.0-kilogram astronaut weighs 638 newtons at the surface of Earth. What is the mass of the astronaut at the surface of the Moon, where the acceleration due to gravity is 1.62 meters per second squared?
65 kg
Double Jeopardy: Two students are pushing a car. What should be the angle of each student’s arms with respect to the flat ground to maximize the horizontal component of the force?
A) 0º
B) 30º
C) 45º
D) 90º
A) 0 degrees
A 30-kilogram boy exerts a force of 100 Newtons on a 50-kilogram object. The force that the object exerts on the boy is
-100 N
Double Jeopardy: What is the magnitude of the force needed to keep a 50.-newton wood block moving across a level, wood table in a straight line at a constant speed of 2.0 meters per second?
15 N
At a certain location, a gravitational force with a magnitude of 350 newtons acts on a 70.-kilogram astronaut. What is the magnitude of the gravitational field strength at this location?
5.0 N/kg or 5 m/s/s
A child pulls a wagon at a constant velocity along a level sidewalk. The child does this by applying a 22-newton force to the wagon handle, which is inclined at 35° to the sidewalk (Note to Rodelli: Draw the picture on the board).
What is the magnitude of the force of friction on the wagon?
18 N
A 25-newton horizontal force northward and a 35-newton horizontal force southward act concurrently on a 15-kilogram object on a frictionless surface. What is the magnitude of the object's acceleration?
0.67 m/s/s
What is the magnitude of the minimum horizontal force needed to start a 300. kilogram steel block on a steel table in motion?
2220 N
A student is standing in an elevator that is accelerating upward. The force that the elevator exerts on the student must be
A) less than the weight of the student when at rest
B) greater than the weight of the student when at rest
C) less than the force of the floor on the student
D) greater than the force of the floor on the student
B. greater than the weight of the student when at rest (acceleration is up so downward force of gravity must be smaller than upward normal force)
The diagram (drawn on board) shows a person exerting a 300.-newton force on the handle of a shovel that makes an angle of 60.° with the horizontal ground.
The component of the 300.-newton force that acts perpendicular to the ground is approximately ______
260 N