Answer:
option (D)
Explanation:
Here initial rotation speed is given, final rotation speed is given and asking for time.
If we use
A) θ=θ0+ω0t+(1/2)αt2
For this equation, we don't have any information about the value of angular displacement and angular acceleration, so it is not useful.
B) ω=ω0+αt
For this equation, we don't have any information about angular acceleration, so it is not useful.
C) ω2=ω02+2α(θ−θ0)
In this equation, time is not included, so it is not useful.
D) So, more information is needed.
Thus, option (D) is true.
Answer:
W = 30.38 N
Explanation:
Given that,
Mass of a rock, m = 3.1 kg
We need to find the weight of the rock on the surface of Earth. Weight of an object is given by :
W = mg
g is the acceleration due to gravity, g = 9.8 m/s²
W = 3.1 kg × 9.8 m/s²
= 30.38 N
So, the weight of the rock on the Earth is 30.38 N.
Answer:
-1786.5J
Explanation:
Temperature 1=T1=25°c
Temperature 2=T2=200°c
Pressure P1=1bar
Pressure P2=0.5bars
T=37°c+273=310k
Note number if moles=1
Recall work done =2.3026RTlogp2/P1
2.3026*8.314*310log(0.5/1)
-1786.5J
Answer:
v= 13 m/s
Explanation:
Velocity is defined as the derivative of displacement with respect to time
v= ds/dt
Known data
s(t) = 5t + 2t² : distance that the ball has rolled after t seconds
vi= 5 m/s : initial velocity
t= 2 s
Problem develoment
s(t) = 5t + 2t²
v= ds/dt= 5 + 4t : velocity of the ball in function of the time
We replace t =2 s in the equation of velocity
v= 5 + 4(2)
v= 13 m/s : velocity after 2 seconds
Answer:
c
Explanation:
because whatever elements are used like gas uses water evaporation so yeah
