Physics Answers

Question 5 (2 points)

When the light crosses a boundary between air and water, the following quantity of light remains the same.

Question 5 options:

A) 

Wavelength

B) 

Frequency

C) 

Speed

D) 

No option is correct

E) 

Both (a) and (b)

Sir Albert Einstein describes light as;

Question 4 options:

A) 

Waves

B) 

No option is correct

C) 

Thermal waves

D) 

Gravitational waves

E) 

Tiny particles 

Unpolarized light with an intensity of 120 W falls on a polarizer and analyser. The angle between the transmission axes of the polarizer and analyser is 72°. What is the intensity of the light leaving the analyser, reaching the photocell?

Question 3 options:

A) 

No option is correct

B) 

11 W

C) 

5.7 W

D) 

60 W

E) 

19 W

Someday a person will walk on Mars, which is 5.6 x 10¹⁰ m from the earth at the closest approach. Determine the minimum time that will be required for a message from Mars to reach the earth via radio waves.

Question 1 options:

A) 

290 s

B) 

No option is correct

C) 

190 s

D) 

490 s

E) 

390 s

A volleyball is served overhead at an angle of 45 degrees above the horizontal at a speed of 9.8m/s. Show that the ball will just barely make it over the net and just about 2 meters on the other side of the net. Use projectile motion and free fall to calculate

a. The initial horizontal and vertical velocity 

b. The time it takes the ball to horizontally reach the net

In Newton’s ring experiment the diameter of 16

th bright ring changes from 1.8 cm to 1.5cm when a liquid is

introduced the plate and the lens. Find the refractive index of the liquid and the diameter of the 5

th dark ring

1. A 550 g mass is tied to a string and made to move in a vertical circle of radius 55 cm at a constant speed. The tension in the string ranges from 2.0 N to 12.7 N. 

a. At what point is the tension a maximum? When is it a minimum?

b. Determine the speed of the mass.

1. A 200 g ball moves in a vertical circle on the end of a 50 cm long string, with no additional input of energy. If its speed at the bottom is 10 m s-1, calculate:

a. The velocity at the top of the circle

b. The tension at the top of the circle

A rollercoaster is designed with a 10 m tall vertical circular loop. Calculate the minimum speed necessary to get around the loop without falling down.

if i double the distance between two objects,what happens to their gravitional force