Answer:
Seriously I have no idea. I need help with my homework.
Explanation:
I really need help with my homework. Sorry
The force of the push and acceleration of the cart are related such as The unbalanced push causes the cart to accelerate.
The work done by the applied force = 650 J
Given the mass of the box = 40 kg
The displacement of the box on applying force = 5 m
Applied horizontal force = 130 N
The co-efficient of friction between box and floor is = 0.3
We have to find the work done by the applied force.
Work done by the applied force = Applied Force x Displacement of the box
= 130 N x 5 m
= 650 J
[Here the unit Nm is known as Joule(J) ]
We have the co-efficient of friction. So,
The force applied due to friction = Mass of the box x Co-efficient of friction x Acceleration due to gravity
= 40 kg x 0.3 x 9.8
= 117.6 N
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The question is incomplete, the complete question is;
A body initially at a all 100 degree centigarde cools to 60 degree centigarde in 5 minutes and to 40 degree centigarde in 10 minutes . What is the temperature of surrounding? What will be the temperature in 15 minutes?
Answer:
See explanation
Explanation:
From Newton's law of cooling;
θ1 - θ2/t = K(θ1 + θ2/2 - θo]
Where;
θ1 and θ2 are initial and final temperatures
θo is the temperature of the surroundings
K is the constant
t is the time taken
Hence;
100 - 60/5 = K(100 + 60/2 - θo)
100 - 40/10 = K(100 + 40/2 - θo)
8= (80 - θo)K -----(1)
6= (70 - θo)K -----(2)
Diving (1) by (2)
8/6 = (80 - θo)/(70 - θo)
8(70 - θo) = 6(80 - θo)
560 - 8θo = 480 - θo
560 - 480 = -θo + 8θo
80 = 7θo
θo = 11.4°
Again from Newton's law of cooling;
θ = θo + Ce^-kt
Where;
t= 0, θ = 60° and θo = 11.4°
60 = 11.4 + C e^-K(0)
60 - 11.4 = C
C= 48.6°
To obtain K
40 = 11.4 + 48.6e^-10k
40 -11.4 = 48.6e^-10k
28.6/48.6 = e^-10k
0.5585 = e^-10k
-10k = ln0.5585
k= ln0.5585/-10
K= 0.0583
Hence, the temperature in 15 minutes;
θ= 11.4 + 48.6e^(-0.0583 × 15)
θ= 31.7°
Answer:
The correct answer is A.
Objects in free fall accelerate due to <u>gravity</u>.
Explanation:
Momentum can help an object to keep its state of motion at a constant velocity when no external force is applied. It can never accelerate the object.
According to the laws of motion, we know that acceleration is produced in a body only when a Force is applied in the direction of motion of body.
During a free fall, only the force of gravity is acting on an object and that too in the direction of its motion. Hence, the acceleration produced in a free falling object is due to gravity.