General 1
The effects that forces can cause are: changes in motion and __________
deformations
Which force keeps planets orbiting?
Gravity
Find the false statement
A. Weight = mass × gravity
B. W = mg
C. Weight is measured in kilograms
D. Gravity on Earth is about 9.8 N/kg
C. Weight is measured in kilograms
(Weight is measured in Newton, Kg are used for mass)
What unit measures force?
Newtons
Which type of force is the magnetic force, distance or non-distance force?
non-distance
Which statements about net force are true?
A. Net force is the total force acting
B. Opposite forces are subtracted
C. Same-direction forces are added
D. Net force always equals zero
A. Net force is the total force acting
B. Opposite forces are subtracted
C. Same-direction forces are added
Which statements about friction are true?
A. Friction opposes motion
B. Friction is always helpful
C. Friction is a contact force
D. Friction can produce heat
A. Friction opposes motion
C. Friction is a contact force
D. Friction can produce heat
The same force is applied on two different objects. One is more massive than the other, which one gains a higher acceleration?
The lighter object
1. Which of the following are contact forces?
A. Friction
B. Gravity
C. Tension
D. Normal force
A. Friction
C. Tension
D. Normal force
Which effects can a force cause?
A. Change in shape
B. Change in speed
C. Change in direction
D. Change in mass
A. Change in shape
B. Change in speed
C. Change in direction
What force stretches springs?
Elastic force
Which statements about Newton’s Third Law are true?
A. Forces come in pairs
B. Action and reaction forces are equal
C. Action and reaction forces act on different objects
D. Action force is always larger
A. Forces come in pairs
B. Action and reaction forces are equal
C. Action and reaction forces act on different objects
Which examples show balanced forces?
A. A lamp hanging still
B. A car speeding up
C. A book on a desk
D. A person standing still
A. A lamp hanging still
C. A book on a desk
D. A person standing still
A net force of 10 N right and 4 N left acts on an object. Which are true?
A. Net force is 6 N right
B. Forces are balanced
C. Object may accelerate right
D. Net force is 14 N
A. Net force is 6 N right
C. Object may accelerate right
What force acts in ropes?
Tension
What F should I apply when I want to accelerate a 2 kg ball to 1 m/s2?
F=m.a
F=2x1=2N
What is Earth’s gravity approximately?
(give units)
9.8 N/kg or m/s22
Which statements about force diagrams are correct?
A. Arrows show force direction
B. Larger arrows can show larger forces
C. Forces are measured in newtons
D. Arrows always point upward
A. Arrows show force direction
B. Larger arrows can show larger forces
C. Forces are measured in newtons
A spring stretches when pulled. Which are true?
A. Elastic force acts
B. The spring changes shape
C. Gravity disappears
D. The spring may return to original shape
A. Elastic force acts
B. The spring changes shape
D. The spring may return to original shape
A net force of 20 N is appplied onto a 6 kg object. Calculate its acceleration ( you have 20 seconds)
F=m . a
20 = 6 . a
a= 20/6=3,333 m/s2