Answer:
2 hours
Explanation:
The motorcycle travels 40 km per hour.
80km / 40km/h = 2 hours.
Answer:
The minimum work per unit heat transfer will be 0.15.
Explanation:
We know the for a heat pump the coefficient of performance (
) is given by
where, 
is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature 
and 
is the required input and is given by 
, 
being magnitude of heat transfer between cyclic device and low-temperature 
. Therefore, from above equation we can write,
Given, 
and 
. So, the minimum work per unit heat transfer is given by
Answer:
Explanation:
Given
--- initial volume
--- initial temperature
--- final temperature
--- coefficient of thermal expansion:
Required
The change in volume
To do this, we make use of cubic expansivity formula
So, we have:
The volume will expand by 
Answer:
F = 19.1 N
Explanation:
To find the force exerted by the string on the block you use the following formula:
(1)
k: spring constant = 95.5 N/m
x: displacement of the block from its equilibrium position = 0.200 m
you replace the values of k and x in the equation (1):
Hence, the force exterted on the block is 19.1 N
Answer:
Explanation:
There will be reaction force by each vertical post on horizontal plank . Let it be R₁ and R₂ . R₁ is reaction force by the post nearer to woman
Taking torque of all forces about the end far away from the woman
Torque by reaction force = R₁ x 5.5
= 5.5 R₁ upwards
Torque by weight of woman in opposite direction , downwards
= - 804 x ( 5.5 - 1.55 )
= - 3175.8
Torque by weight of the plank in opposite direction , downwards .
= - 27 x 5.5 / 2
= - 74.25
Torque by R₂ will be zero as it passes through the point about which torque is being taken .
Total torque
= 5.5 R₁ - - 3175.8 - - 74.25 = 0 ( For equilibrium )
5.5 R₁ = 3250
R₁ = 590.9 N .
