A box is lowered using a rope. If the acceleration of the box, is 3.3 m/s2 (downward) and its mass is 29.1 kg, what is the magni
1 answer:
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Answer:
<em>The force required is 3,104 N</em>
Explanation:
<u>Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:
Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:
We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:
The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:
F= 3,104 N
The force required is 3,104 N
<u>Answer:</u> The correct answer is Option b.
<u>Explanation:</u>
Young's Modulus is defined as the ratio of stress acting on a substance to the amount of strain produced.
Stress is defined as force per unit area and strain is defined as proportional deformation in a material.
The equation representing Young's Modulus is:
where,
Y = Young's Modulus
F = force exerted by the weight
l = length of wire
A = area of cross section
= change in length
Hence, the correct answer is Option b.