Answer: 0.5 seconds or 2.625 seconds
Explanation:
At t = 0, The ball is 4 ft above the ground.
The height of the football varies with time in the following way:
s(t) = -16 t² + 50 t + 4
we need to find the time in which the height would of the football would be 25 ft:
⇒25 = -16 t² + 50 t + 4
we need to solve the quadratic equation:
⇒ 16 t² - 50 t + 21 = 0
⇒ t = 0.5 s or 2.625 s
Therefore, at t = 0.5 s or 2.625 s, the football would be 25 ft above the ground.
Answer:
T = 17649.03 N = 17.65 KN
Explanation:
The tension in the cable must be equal to the apparent weight of the passenger. For upward acceleration:
where,
T = Tension in cable = ?
= Apparent weight
m = mass = 1603 kg
g = acceleration due to gravity = 9.81 m/s²
a = acceleration of elevator = 1.2 m/s²
Therefore,
<u>T = 17649.03 N = 17.65 KN</u>
During the year, the seasons change depending on the amount of sunlight reaching the Earth<span> as it revolves around the Sun. The seasons are </span>caused<span> as the </span>Earth<span>, </span>tilted<span> on </span>its axis<span>, travels in a loop around the Sun each year. </span>
The final velocity of the projectile when it strikes the ground below is 198.51 m/s.
<h3>
Time of motion of the projectile</h3>
The time taken for the projectile to fall to the ground is calculated as follows;
h = vt + ¹/₂gt²
where;
- h is height of the cliff
- v is velocity
- t is time of motion
265 = (185 x sin45)t + (0.5)(9.8)t²
265 = 130.8t + 4.9t²
4.9t² + 130.8t - 265 = 0
solve the quadratic equation using formula method,
t = 1.89 s
<h3>Final velocity of the projectile</h3>
vyf = vyi + gt
where;
- vyf is the final vertical velocity
- vyi is initial vertical velocity
vyf = (185 x sin45) + (9.8 x 1.89)
vyf = 149.322 m/s
vxf = vxi
where;
- vxf is the final horizontal velocity
- vxi is the initial horizontal velocity
vxf = 185 x cos(45)
vxf = 130.8 m/s
vf = √(vyf² + vxf²)
where;
- vf is the speed of the projectile when it strikes the ground below
vf = √(149.322² + 130.8²)
vf = 198.51 m/s
Learn more about final velocity here: brainly.com/question/6504879
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An object's momentum will change if there is a non-zero net external force acting on it. This assertion is true.
<h3>
</h3><h3>What is momentum?</h3>
The momentum is defined as the product of mass and the velocity of the body. It is denoted by the letter P. It occurs due to the applied force. Its unit is Kg m/s².
p=mΔV
If there is a change in the velocity there must be a force acting on the object.
If an object is acted on by a non-zero net external force, its momentum will not remain constant. is an accurate statement.
<h3>
</h3>
Hence, option B is correct.
To learn more about the momentum refer to the link;
brainly.com/question/4956182
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