# Forces Review.

## Presentation on theme: "Forces Review."— Presentation transcript:

Forces Review

Which of the following is the cause of an acceleration or a change in an object’s motion?
speed inertia force velocity

Which of the following forces is an example of a field force?
gravitational force frictional force normal force tension

A cart is pushed with an acceleration of 2 m/s2. If µ = 0
A cart is pushed with an acceleration of 2 m/s2. If µ = 0.5, what does the net force equal? FA FFr FA – FN FA – FFr

An army ranger is lifted by a cable to a helicopter at a constant velocity?
Fg FT – Fg Fg – FT

A bike is coasting to a stop. What is the net force equal to?
Gravitational Force Zero Frictional Force Normal Force

Which of the following is the tendency of an object to maintain its state of motion?
acceleration inertia force velocity

An object with a mass of 100kg has what weight in Newtons?
9.8 980 500

With a constant applied force, mass is directly proportional to acceleration. This statement describes which of Newton’s Laws? 1st 2nd 3rd None of the above

If a nonzero net force is acting on an object, then the object is definitely
at rest. moving with a constant velocity. being accelerated. losing mass.

Which are simultaneously equal but opposite forces resulting from the interaction of two objects?
net external forces field forces gravitational forces action-reaction pairs

What is not true regarding action reaction forces?
They are an application of Newton’s 3rd Law. They act on the same object. They act on different objects. All are true.

The magnitude of the force of gravity acting on an object is
frictional force. weight. inertia. mass.

In the terminology “a 500-N block”, the 500-N refers most specifically to the block's:
mass. force. weight. None of the above.

It is generally easier to overcome friction when an object is moving than at rest because …
µk is greater than µs µs is greater than µk Fg increases when an object moves Fg decreases when an object moves

As a car coasts on a level road yet slows down, the net force acting on the tires is:
greater than the normal force times the coefficient of static friction. equal to the normal force times the coefficient of static friction. the normal force times the coefficient of kinetic friction. zero.

If an object changes its direction of motion:
the mass of the object had to change. the inertia of the object had to change. the speed of the object stays the same. a force must have been applied to the object.

If no forces are acting on an object, its motion will:
continue in the same direction with the same speed. slow down and eventually stop. continue at the same speed but could change direction. continue in the same direction but could change speed.

If the net force is negative and the speed is positive:
the speed will decrease over time. the speed will increase over time. the speed will stay the same. the speed will immediately drop to zero.

Which of the following will not change as you increase the slope of a ramp?
Normal Force Fgx coefficient of friction Fgy

Which of the following about an object on a ramp will increase if you decrease the slope of a ramp?
Frictional Force Gravitational Force Fgx Coefficient of Friction

What happens to the normal force as the angle of a ramp increases?
Normal force increases Normal force decreases Normal force remains constant

What happens to the coefficient of friction as the angle of a ramp increases?
µ decreases µ remains constant

The gravitational force on an object is 98N
The gravitational force on an object is 98N. What is the object’s mass in kg? 98 9.8 980 10

A 1000kg car is at rest on a slope of angle 10o
A 1000kg car is at rest on a slope of angle 10o. What equals the normal force? Fg Fg sin10 Fg cos10 Fg tan10 FFr

A 1000kg car is at rest on a slope of angle 10o
A 1000kg car is at rest on a slope of angle 10o. What equals the frictional force? Fg Fg sin10 Fg cos10 Fg tan10 FFr