Practice Test 1

Question 1

Apollo 11 continued to fly towards the moon even after the engines were turned off. This illustrates

Answer 1

Newton’s first law.
An object at rest remains at rest unless acted on by a net force, and an object in motion remains in motion with constant velocity unless acted on by a net force.

Question 2

A satellite is put into circular orbit around a planet of mass B. If the satellite’s velocity is s ms^-1, what is the radius of the orbit?

Answer 2

GB/S^2

Fc= mv^2/r
Fc=ms^2/r
F= GBm/r^2
Fc=F
ms^2/r=GBm/r^2
r=GB/S^2

Question 3

Two blocks who’s masses are m1 and m2 start from rest and slide down two planes of equal length inclined at angles of Θ1 and Θ2 respectively. Given that the coefficient of kinetic friction is equal in both cases, that m1>m2 and that Θ1>Θ2 whats true?

Answer 3

Regardless of their masses, m1 slides down faster because of the larger angle of inclination.

Question 4

An object weights 180N @ earths surface. How much would it weight if the distance from the earth center were tripled?

Answer 4

20N

Question 5

The image formed by a diverging lens is always

Answer 5

Virtual, Erect and reduced.

Question 6

For most liquids, viscosity,

Answer 6

increases as temperature decreases.

Viscosity is a measure of internal friction in a liquid and greater internal friction means more resistance to flow.

Question 7

A penny is placed at the bottom of a beaker of water and appears to be closer to the surface than it actually is. This is due to the phenomenon of

Answer 7

refraction

Question 8

Light of 589nm (yellow) passes from air into a medium of higher density. The ratio of the index of refraction of the medium of that of air is unknown. What additional information is needed to determine the angle of reflection of the incident light at the air-medium boundary?

Answer 8

Angle of refraction of the incident light.

Question 9

an object is place with a distance x in front of a convex mirror of unknown focal length. What can be said about the image formed?

Answer 9

It is virtual and erect.

Question 10

Both the length and diameter of a cylindrical-snapped asbestos resistors are reduced by factor of 2. In what way are the resisting properties affected?

Answer 10

The resistance increases by a factor of 2.

Question 11

if the index of refraction of ground glass is 2 and the index of refraction of air is 1, what is the critical angle of a light ray passing from ground to air?

Answer 11

30 degrees.

The critical angle is the angle such that the refracted ray makes an angle of 90 degrees with the normal to the interface.

Question 12

A concave mirror of local length F forms a virtual image. The object must be placed.

Answer 12

Between F and the mirror.

A virtual image formed by a mirror is an image that is located behind the mirror and the have a negative image distance.
Concave mirrors have a positive focal length