Answer:
the answers are
W = 1271.256 J
= 361.81 J
Explanation:
The mass of the trunk (m) = 46kg
angle between the ramp and the horizontal (θ) = 42°
The trunk is pulled at a displacement (d) up the ramp = 3m
The coefficient of kinetic friction between the trunk and the ramp = 0.36
The trunk is moving with a constant velocity therefore the net force on it is zero, therefore the force required to move the trunk must be equal to the summation of forces opposing the trunk
The two forces opposing the trunk are
- the gravitational force directed down the ramp
and - the frictional force between the ramp and the trunk
We have to calculate the machine's force which is equal to sum of the
= 
θ
μ× N
N = mgcosθ
μ
θ
F = mg (sinθ + μcosθ)
F = 46× 9.8 (sin42 + 0.36×cos42)
F= 450.8 (0.67 +0.27)
F = 450.8 × 0.94
F = 423.752N
to calculate the workdone on the trunk by the machine force
The workdone on the trunk is = W = F × dcosΘ
Θ = 0° because the trunk is directed parallel to the ramp
W =423.752× 3 cos 0
W = 423.752 ×3
W = 1271.256 J
(b) the increase in thermal energy of the trunk and the ramp
Friction converts mechanical energy into thermal energy, so multiplying the frictional force with the distance gives the thermal energy generated by the trunk
× d
= μθ ×d
= 0.36 ×46×9.8×cos42×3
= 361.81 J
Speed with which initially car is moving is 21 m/s
Reaction time = 0.50 s
distance traveled in the reaction time d = v t
d = 21 * 0.50 = 10.5 m
deceleration after this time = -10 m/s^2
now the distance traveled by the car after applying bakes
so total distance moved before it stop
d = 22.05 + 10.5 = 32.55 m
so the distance from deer is 35 - 32.55 = 2.45 m
now to find the maximum speed with we can move we will assume that we will just touch the deer when we stop
so our distance after brakes are applied is d = 35 - 10.5 = 24.5 m
again by kinematics
so maximum speed would be 22.1 m/s
Explanation:
the velocity graph of a ball mass 20mg moving along a straight line
Answer:
The difference between ice and steam in Celsius (Centigrade) is 100 deg.
So the difference between and 4 cm and 24 cm of the thread corresponds to 100 deg C.
So 8 cm is 4 cm greater than the ice point
4 cm / 20 cm = 1/5 since the steam point and the ice point are 20 cm apart
Then 1/5 * 100 deg C = 20 deg C the requested temperature
Answer:
the car would arrive after 10 hr to Austin.
Explanation:
bus average from amarllo to austin = 60 miles per hour
time takne by bus to reach austin = 8 hr
automobile average from amarllo to austin = 60 miles per hour
from the information given in the question:
60 mph --- 8 h
48 mph --- x h
By using The inverse variation:
60 : 48 = x : 8
60* 8 = 48* x
480 = 48*x
x = 480/48
x = 10 h
the car would arrive after 10 hr to Austin.
