Answer:
R=19.5m
= 4.65° S of W
Explanation:
Refer the attached fig.
displacement of the x and y components
x-component displacement is () =
= A (20°) + B
(40°)
= -12.0(20°) + 20.0
(40°)
= -19.425m
x-component displacement is () =
= A (20°) - B
(40°)
= 12.0(20°) - 20.0
(40°)
= -1.579
resultant displacement
∴
R =
=
=19.5m
=
=
= 4.65° S of W
Answer:
speed of boat as
river speed is given as
Explanation:
When boat is moving down stream then in that case net resultant speed of the boat is given as
since the boat and river is in same direction so we will have
Now when boat moves upstream then in that case the net speed of the boat is opposite to the speed of the river
so here we have
as we know when boat is in downstream then in that case it covers 24 miles in 2 hours
also when it moves in upstream then it covers same distance in 3 hours of time
so we have speed of boat as
river speed is given as
Answer:
1)H=714 Watts of energy is given out.
2)614.34 KCal energy is burnt in an hour in the room
3)In freezing conditions, 1337.09 KCal is spent in an hour.
Explanation:
The formula for thermal conductivity states that the rate of heat loss H is as follows:
H= where,
K=Coefficient of thermal conductivity
A=Area of Cross Section
H=Rate of heat loss
x=Thickness of the material
=Temperature difference between the two surfaces of the body in context
=37°C ie. Body Temperature
=20°C ie. Room Temperature
For first case, =17°C or 17°F
K for fat= 0.21
A=2
x=0.01 m
H=
H=714 Watts of energy is given out.
2) ×
Energy= 714 × 60 × 60=2570400 J
2570400 J=614.3403442 KCal
Therefore, 614.3403442 KCal energy is burnt in an hour.
3) Only the temperature difference becomes 37°C from 17°C , rest everything remains the same, therefore the energy will also vary due to the temperature factor and more energy will be spent as in freezing climate °C
E==1337.09 KCal
In freezing conditions, 1337.09 KCal is spent in an hour.