Using the kinematic equation V=Vo + at, the initial velocity (Vo) is -32, the acceleration (a) is found by dividing force by mass 55N/.06kg=916.66 m/s/s, and the time is 0.045 sec.
V=Vo+at
V=-32+916.66*.045
V=9.25
The answer is A.
Explanation:
Total Resistance: 3+2 = 5 ohms
V=9V
Power = V²/R
=9²/5
=81/5
=16.2 W
I assume the 100 N force is a pulling force directed up the incline.
The net forces on the block acting parallel and perpendicular to the incline are
∑ F[para] = 100 N - F[friction] = 0
∑ F[perp] = F[normal] - mg cos(30°) = 0
The friction in this case is the maximum static friction - the block is held at rest by static friction, and a minimum 100 N force is required to get the block to start sliding up the incline.
Then
F[friction] = 100 N
F[normal] = mg cos(30°) = (10 kg) (9.8 m/s²) cos(30°) ≈ 84.9 N
If µ is the coefficient of static friction, then
F[friction] = µ F[normal]
⇒ µ = (100 N) / (84.9 N) ≈ 1.2
B
Think of inertia of getting into a car accident without a seat belt although the car stops you will not you would likely fly out the window
1. Define Newtons second law of motion (this will help put things into perspective)
2.Get the mass of the object (in this case 75 kg)
3.The net force acting on the object...find it (in this case 500 N)
4.Change the equation to F=ma (500=75a)
5.Divide both sides by 75 and that is the acceleration.
