Physics

Question 1

We use models in physics because?

Answer 1

The real world is too complicated and we choose to ignore certain factors

Question 2

How many significant figures are there in 7.3400?

Answer 2

5

Question 3

Is the value of displacement always the same as the distance travelled?

Answer 3

No, the distance can be greater than the value of displacement

Question 4

We assume that acceleration is constant. Why?

Answer 4

Because we would need to use calculus when the acceleration is not constant

Question 5

Does negative acceleration mean deceleration?

Answer 5

No

Question 6

In order to use equations (2.75), (2.76) and (2.77), we have to choose a coordinate system such that?

Answer 6

The y-axis points upwards

Question 7

The graphical method of adding vectors is called?

Answer 7

The head-to-tail method

Question 8

Can we subtract vectors graphically?

Answer 8

Yes, because subtracting a vector is the same as adding the opposite vector

Question 9

When adding two vectors, the magnitude of the resultant vector?

Answer 9

Can be smaller than the sum of the magnitudes of the addends

Question 10

The horizontal component of velocity of an object in a projectile motion

Answer 10

Is always constant but not zero

Question 11

The vertical component of velocity of an object in projectile motion

Answer 11

Linearly depends on time

Question 12

The vertical component of acceleration of an object in a projectile motion

Answer 12

Is always constant but not zero

Question 13

The horizontal component of acceleration of an object in a projectile motion

Answer 13

Is always zero

Question 14

In figure 3.47, Vboat is

Answer 14

The velocity of the boat relative to the water

Question 15

In figure 3.48, Vw is

Answer 15

Velocity of the wind relative to the ground

Question 16

Equation (3.91) is an application of equation (3.75) to the situation shown in figure 3.48. What’s wrong with equation (3.91)?

Answer 16

When the angle is defined as in figure 3.91, we can not apply equation (3.75)

Question 17

The greater the net external force acting on an object,
A) The faster the object moves
B) The slower the object moves

Answer 17

Neither of the above is true

Question 18

A free-body diagram is

Answer 18

A drawing of all external forces acting on a body

Question 19

The net force acting on an object that is in a free-falling motion

Answer 19

Is equal to the gravitational force due to the earth

Question 20

The tension in a cable is

Answer 20

A pulling force along the direction of the cable

Question 21

The magnitude of the kinetic frictional force on an object

Answer 21

Is equal to the normal force multiplied by the coefficient of kinetic friction

Question 22

The magnitude of the static force on an object

Answer 22

Can be less than the normal force multiplied by the coefficient of static friction

Question 23

A drag force is

Answer 23

The resistant force when an object moves in a fluid

Question 24

How does a drag force depend on velocity?

Answer 24

The greater the velocity, the greater the drag force

Question 25

If you drop a stuffed animal from the CN tower, the toy will

Answer 25

Reach a constant velocity called terminal velocity