Answer:
160J
Explanation:
Given force = 8N and total distance = 20 meters
Workdone = force x distance
= 8 x 20
= 160J
Therefore, workdone by Riley in pulling the hoover is 160J
Not sure... need help with it
Answer:3.56 nanosecond
In this case, you are asked the time and given the light distance(3.5ft)
To answer this question you would need to know the velocity of light. Speed of light is <span>299792458m/s. Then the calculation would be:
time= distance/speed
time= 3.5 ft / (</span>299792458m/s) x 0.3048 meter/ 1 ft= 3.56

second or 3.56 nanosecond
Answer:
D) True. the protostar rotates more quickly.
Explanation:
If the system is isolated, the angular momentum must be retained.
Initial
L₀ = I w₀
Final
=
L₀ = 
I w₀ = 
= I /
w₀
In general, the radius of the cloud decreases significantly to form the star, the moment of inertia must decrease, so the angular velocity must increase
Let's examine the answers
A) False. The opposite happens
B) False. Speed changes
C) False. For this there must be an external force, which does not exist
D) True. You agree with the above