Answer:
120 rpm
Explanation:
I1 = 105 kgm^2, I2 = 70 kgm^2
f1 = 80 rpm, f2 = ?
Let the angular speed be f2 when his arms are tucked.
If no external torque is applied, then the angular momentum remains constant.
L1 = L2
I1 w1 = I2 w2
I1 x 2 x 3.14 x f1 = I2 x 2 x 3.14 x f2
105 x 80 = 70 x f2
f2 = 120 rpm
Answer:
The acceleration caused by a net force of 2 N on a 2 kg mass is 1 m/s²
Explanation:
The given parameters on an applied force is as follows;
The acceleration given to a 1 kg mass by a 1-N net force = 1 m/s²
According to Newton's second law of motion, the acceleration, "a", given to an object by a force, "F", is proportional to the magnitude of the net force
Therefore, we have;
F ∝ a
The constant of proportionality is given as the mass, "m", of the object, therefore, we have;
F = m × a
The acceleration given to a 2 kg mass by a 2-N net force is given therefore, given as follows;
2 N = 2 kg × a
a = 2 N/(2 kg) = 1 m/s²
The acceleration, "a", caused by a net force of 2 N on a 2 kg mass is a = 1 m/s².
Answer:
0.47m3
Explanation:
Volume = Mass / Density
In this case:
Mass - 1280 kg
Density - 2700kg/m3
1280 / 2700 = 0.4740741m3
When this is rounded off ( 2 d.p ):
0.47 m3
HOPE THIS HELPED
Answer:
Turns ratio=108, Pin= 110.5 W, Current ratting= 920mA
Explanation:
Vp=120 V(rms)
Vs=13,000 V (rms)
Is = 8.50*10^-3 V(rms)
a.
secondary to primary turn ration:
Ns/Np=Vs/Vp
=
=
= 108
b.
Is=8.50 mA (rms)
As Vs= 13,000V (rms)
For ideal transformer
Pin=Pout______(1)
Pout= Is*Vs (put in equ 1)
Pi=Is*Vs
Pi=(8.50*10^-3)*(13,000) W
Pi=110.5 W
Power supplied will be 110.5 W.
c.
We have to find the current passing through primary circuit to find current rating of fuse in primary circuit.
For ideal case
Ip*Vp= Is*Vs
Ip=
Ip= (13000*8.5*10^-3)/120
Ip=920 mA
In primary circuit fuse current rating will be 920 mA.
Answer:
98J
Explanation:
Given parameters:
Mass of rock = 5kg
Height = 2m
Unknown:
Work done = ?
Solution:
The amount of work done is given as:
Work done = Force x distance
Work done = Weight x height
Work done = mgH
Now insert the parameters and solve;
Work done = 5 x 9.8 x 2 = 98J