Explanation:
Given: Initial Velocity=0
Final Velocity= 20 m/s
Time= 4 s
Accleration: Unknowns
Use kinematic equation
so a = 5 m/s^2
Answer: B. A magnet pulls a nail towards it
Explanation: Out of the list of answers, this is the only answer where a force is acting on an object. the act of the magnet pulling on the nail is the force, and the nail is the object.
The initial speed of the bolt is not 58.86 m/s.
Let a be the acceleration of the rocket.
During the 4 sec lift off, the rocket has reached a height of
h = (1/2)*a*t^2
with t=4,
h = (1/2)*a^16
h = 8*a
Its velocity at 4 sec is
v = t*a
v = 4*a
The initial velocity of the bolt is thus 4*a.
During the 6 sec fall, the bolt has the initial velocity V0=-4*a and it drops a total height of h=8*a. From the equation of motion,
h = (1/2)*g*t^2 + V0*t
Substituting h0=8*a, t=6 and V0=-4*a into it,
8*a = (1/2)*g*36 - 4*a*6
Solving for a
a = 5.52 m/s^2
The height of the bullet when the velocity is zero is 256 ft.
<h3>Height of the bullet when the velocity is zero </h3>
The height of the bullet when the velocity is zero is determined by taking derivative of the function as shown below;
The height of the bullet at this time is calculated as follows;
Learn more about height of projectiles here: brainly.com/question/10008919
Answer:
1.63 N
Explanation:
F = GMm/r^2
= (6.67x10^-11)(10x10^5)(3x10^5) / 3.5^2
= 1.63 N ( 3 sig. fig.)
