Answer: Impulse = 4 kgm/s
Explanation:
From the question, you're given the following parameters:
Momentum P1 = 12 kgm/s
Momentum P2 = 16 kgm/s
Time t = 0.2 s
According to second law of motion,
Force F = change in momentum ÷ time
That is
F = (P2 - P1)/t
Cross multiply
Ft = P2 - P1
Where Ft = impulse
Substitute P1 and P2 into the formula
Impulse = 16 - 12 = 4 kgm/s
The magnitude of the impulse is therefore 4 kgm/s.
Answer:
As the car travels up the coaster it is gaining potential energy.
Explanation:
Because It has the greatest in amount of potential energy at the top of the coaster. when the car travels down the roller coaster it obtains speed and kinetic energy.
Answer:
Intensity, 
Explanation:
Power of the light bulb, P = 40 W
Distance from screen, r = 1.7 m
Let I is the intensity of light incident on the screen. The power acting per unit area is called the intensity of the light. Its formula is given by :




So, the intensity of light is
.
Answer:
a. wavelength of the sound, 
b. observed frequecy, 
Given:
speed of sound source,
= 80 m/s
speed of sound in air or vacuum,
= 343 m/s
speed of sound observed,
= 0 m/s
Solution:
From the relation:
v =
(1)
where
v = velocity of sound
= observed frequency of sound
= wavelength
(a) The wavelength of the sound between source and the listener is given by:
(2)
(b) The observed frequency is given by:


(3)
Using eqn (2) and (3):


I think it’s C. But I’m not completely sure.