4) B) Speed = Distance/ time
5) C) By applying second law of newton " F = ma" we say that "15 = 12 × acceleration"
15/12= acceleration
acceleration = 1.25 m/s2
6) D) It will continue to accelerate to the right but at a slower rate because of the small force (F2) being applied from the right.
∵∴∵∴∵∴∵∴
⊄L∅∪⊥ G∀NG
∵∴∵∴∵∴∵∴
Given:
u=0 m/s
a=1.1 m/s^2
S=5 m
t=time it takes to run 5 m
Use the kinematics equation
S=ut+(1/2)at^2
=>
5=0*t+(1/2)1.1(t^2)
solve for t
t=sqrt(5*2/1.1)=3.015 seconds.
Answer:
15.64 KN
Explanation:
mass of the elevator cab with a single occupant= 2300 kg
acceleration relative to the cab
= 6.80 m/s^2
acceleration of the coin relative to the cab in the opposite direction of motion of cab so we can consider it as a= -6.80 m/s^2
The acceleration of elevator cab relative to the ground 
now we can say that

=-6.80+ a_{eg}= -9.8
[tex]a_{eg}=-9.8+6.80=-3.8
The forces that act on elevator cab are tension and gravitational, applying newtons second law
T- mg= ma_{eg}
Then the tension in the cable is
T= 2300(-3.8)+2300×9.8= 15640 N= 15.64 KN
therefore tension in the string will be 15.64 KN
Facing disagreement forces scientists to prove their theories more conclusively.