Answer:

Explanation:
Time to mow 1 lawn by Wilma is 80 minutes
so work done in 1 minute by Wilma is given as
Similarly Rocky mow same lawn in 120 minute
so work done in 1 minute by Rocky is given as

now we know that they both worked by "t" time
so total work performed by them

they both mow 2 lawns then it is given as


Answer:
4 m/s
Explanation:
speed = distance/time
speed= 20/5 = 4
similarly for all no. the answer is constant,i.e. 4
Answer:
The atmospheric pressure is
.
Explanation:
Given that,
Atmospheric pressure
drop height h'= 27.1 mm
Density of mercury 
We need to calculate the height
Using formula of pressure

Put the value into the formula



We need to calculate the new height




We need to calculate the atmospheric pressure
Using formula of atmospheric pressure

Put the value into the formula


Hence, The atmospheric pressure is
.
Answer: 47.6 m/s
Explanation: Please see attached for the calculation and formula.
Answer:
Explanation:
N = 65
Area, A = 0.1 x 0.2 = 0.02 m^2
R = 10 ohm
ω = 29.5 rad/s
B = 1 T
(a) at t = 0
e = N x B x A x ω
e = 65 x 1 x 0.02 x 29.5
e = 38.35 V
(b) The maximum rate of change of magnetic flux is equal to the maximum value of induced emf.
Ф = 38.35 Wb/s
(c) e = NBAω Sinωt
e = 65 x 1 x 0.02 x 29.5 x Sin (29.5 x 0.05)
e = 38.174 V
(d) Maximum torque
τ = M B Sin 90
τ = N i A B
τ = N e A B / R
τ = 65 x 38.35 x 0.02 x 1 / 10
τ = 5 Nm