Answer:
Explanation:
Let the force applied by her be T on the rope . This force will create tension in the rope. It will act in upper direction on the crates . The weight of the crate will act in downward direction .
Net force on the crate = mg - T in downward direction
Applying Newton's law
mg - T = m a
a =0 ( speed is steady )
mg - T = 0
T = mg
= 25 x 9.8
= 245 N
Force to be applied by her
= 245 N
Answer:
Work = Work out
Work in = 5 N * d where d is the distance the handle travels
Work out = 50 N * 7 m = 350 Joules
d = 50 N * 7m / 5 N = 70 m
This is the distance traveled by the force of 5 N
Momentum = Mass × Velocity
From the given data, Mass is 1000kg and Velocity is 20m/s
Momentum = 1000 × 20
The value of the acceleration is 0.76 m/s² and the total time taken by the vehicle is 39 seconds.
<h3>Acceleration of the vehicle</h3>
The acceleration of the vehicle before coming to rest is calculated as follows;
v² = u² + 2as
where;
- v is the final velocity
- u is the initial velocity
- a is the acceleration
- s is the distance traveled before stopping
the car came to rest with constant velocity attained after 12 seconds.
the initial velocity of the car before 12 seconds is zero.
v² = 0 + 2as
a = v²/2s
a = (10²)/(2 x 66)
a = 0.76 m/s²
<h3>Time of motion of the vehicle</h3>
d = ut + ¹/₂at²
where;
- d is the total distance traveled
- t is the time of motion
- a is acceleration
- u is initial velocity of the vehicle
580 = 0 + ¹/₂(0.76)t²
580 = 0.38t²
t² = 580/0.38
t² = 1,526.3
t = √1,526.3
t = 39 seconds
Thus, the value of the acceleration is 0.76 m/s² and the total time taken by the vehicle is 39 seconds.
Learn more about time of motion here: brainly.com/question/2364404
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