Answer:
I just want the points but you should pay attention in class jk
Explanation:
When a man falls on a hard cemented floor his momentum reduced to zero in a very short time and hurt the man. Whereas when a man falls on a heap of sand. As sand can compress, it takes longer time for the man to hit the ground (or hard surface)
Answer:
Pi(3.14) radians or 180º degrees
Explanation:
First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.
The formula is:
where l = wavelength in meters
With current values:
l = 336 [m/s]/420[1/s] = 0.8 meters
Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.
Answer:
θ=108rad
t =10.29seconds
α=-8.17rad/s²
Explanation:
Given that
At t=0, Wo=24rad/sec
Constant angular acceleration =30rad/s²
At t=2, θ=432rad as it try to stop because the circuit break
Angular motion
W=Wo+αt
θ=Wot+1/2αt²
W²=Wo²+2αθ
We need to find θ between 0sec to 2sec when the wheel stop
a. θ=Wot+1/2αt²
θ=24×2+1/2×30×2²
θ=48+60
θ=108rad.
b. W=Wo+αt
W=24+30×2
W=84rad/s
This is the final angular velocity which is the initial angular velocity when the wheel starts to decelerate.
Wo=84rad/sec
W=0rad/s, because the wheel stop at θ=432rad
Using W²=Wo²+2αθ
0²=84²+2×α×432
-84²=864α
α=-8.17rad/s²
It is negative because it is decelerating
Now, time taken for the wheel to stop
W=Wo+αt
0=84-8.17t
-84=-8.17t
Then t =10.29seconds.
a. θ=108rad
b. t =10.29seconds
c. α=-8.17rad/s²
Answer:
1.22gcm³
Explanation:
D = mass/ volume
Mass=1.840kg = 1,840g
1000g = 1kg
1.840kg= x(g)
X(g) = 1.840/1000
= 1840g
Volume = 0.0015m³= 1,500cm³
1m³= 1000,000cm³.
0.0015m³= x(cm³)
X(cm³) = 1000,000×0.0015
X(cm³)= 1500.
Since density is mass/volume, now impute your data's
D=m/v
D=1840/1500
1.22g/cm³
