The document contains a post-test physics exam with 5 multiple choice questions and 3 essay questions. The multiple choice questions involve calculating displacements, accelerations, angular positions, and projectile motion. The essay questions require calculating position, velocity, acceleration, angular position, and projectile motion coordinates at given times using kinematic equations.

1. Post Test 1 Physics
Objective
1. A particle is initially at r1 = 3i + 2j and the moving to r2 = -i + 5j. The magnitude of the
displacement of particle is ....
a. 2
b. 3
c. 4
d. 5
e. 6
2. Position of a particle is described by equation x = t3 - 3t2 + 5t. The acceleration of the
particle at t = 2 s is ....
a. 4 m/s2
b. 6 m/s2
c. 7 m/s2
d. 8 m/s2
e. 9 m/s2
3. A wheel can rotate with equation Ө = 2t2 - 16t + 8, where Ө and t are measured in
rad and s respectively. A wheel will stop to move after ....
a. 4 s
b. 7 s
c. 10 s
d. 14 s
e. 19 s
4. A disk rotates with equation ω (t) = (3t2 + 4) rad/s. Determine the angle position at a
point which is located on the border of the disk at t = 2 s, if the initial angle position
is zero.
a. 4 rad
b. 8 rad
c. 12 rad
d. 16 rad
e. 18 rad
5. A stone is thrown with initial velocity 40 m/s that makes an angle of 370 Position of
particle at t = 1 s after thrown is ....
a. (24 ; 15) m
b. (32 ; 15) m
c. (19 ; 32) m

2. d. (32 ; 19) m
e. (15 ; 32) m
Essay
1. A body is moving with the initial velocity 20 m/s. If the acceleration of the body is
given (4t + 2) m/s2 and the initial position is zero. Calculate :
1) The position of the body at t = 2 s
2) The velocity of the body at t = 2s
3) The acceleration of the body at t = 2 s
2. The angular position of point material to a disc is given by the equation Ө = 5 - 3t +
2t2. Calculate :
1) The angular position from t = 2s
2) The average angular velocity at time between t = 0 and t = 2 s
3. A projectile is fired with initial velocity 20 m/s and at an angle of elevation of 300. If
the acceleration of gravitational is 10 m/s2. Calculate :
1) The coordinate of the projectile at the highest point
2) The position of the projectile when it touches the ground
Solution : objective
1. Know : r1 = 3i + 2j
r2 = -i + 5j
Ask : IΔrI = ....?
Solution :
Δr = r2 - r1
= (-i + 5j) - (3i + 2j)
= -4i + 3j
IΔrI = √
=√
=√
= 5 {D}
2. Know : x = t3 - 3t2 + 5t
t=2s
Ask : a = ....?

3. Solution :
x = t3 - 3t2 + 5t
v = 3t2 - 6t + 5
a = 6t - 6
= 6 (2) - 6
= 12 - 6
= 6 m/s2 {B}
3. Know : Ө = 2t2 - 16t + 8
Ask : t when the wheel will stop = ....?
Solution :
Ө = 2t2 - 16t + 8
ω = 4t - 16
0 = 4t - 16
16 = 4t
4=t
So, the t when the wheel will stop = 4 s {A}
4. Know : ω (t) = (3t2 + 4) rad/s
t=2s
Ө0 = 0
Ask : Ө = ....?
Solution :
ω = (3t2 + 4)
Ө = Ө0 + t3 + 4t
= 0 + 23 + 4 (2)
=0+8+8
= 16 rad {D}
5. Know : v0 = 40 m/s
α = 370
t=1s
Ask : Position = ....?
Solution :
vbx = v0 . cos α . t
= 40 . cos 370 . 1
= 40 . 0,8 . 1
= 32

4. vby = v0. sin α . t - ½ . g . t2
= 40 . sin 370 . 1 - ½ . 10 . 12
= 40 . 0,6 . 1 - ½ . 10 . 12
= 24 - 5
= 19
So, the position is (32 ; 19) m {D}
Solution : essay
1. Know : v0 = 20 m/s
a = (4t + 2) m/s2
s0 = 0
Ask : 1) s when t = 2 s
2) v when t = 2 s
3) a when t = 2 s
Solution :
a = 4t + 2
v = 2t2 + 2t
s = t3 + t 2
1) s = 20t + t3 + t2
= 20(2) + (23) + 22
= 40 + +4
= 49,3 m
2) v = v0 + (2t2 + 2t)
= 20 + 2 (22) + 2 (2)
= 20 + 8 + 4
= 32 m/s
3) a = 4t + 2
= 4 (2) + 2
=8+2
= 10 m/s2
2. Know : Ө = 5 - 3t + 2t2
Ask : 1) Ө when t = 2 s
2) ̅ at time between t = 0 and t = 2 s

5. Solution :
1) Ө = 5 - 3t + 2t2
= 5 - 3 (2) + 2 (22)
=5-6+8
= 7 rad
2) t1 = 0, Ө1 = 5 - 3 (0) + 2 (02)
= 5 rad
t2 = 2, Ө2 = 5 - 3 (2) + 2 (22)
=5-6+8
= 7 rad
̅= = = = 1 rad/s
3. Know : v0 = 20 m/s
α = 300
g = 10 m/s2
Ask : 1) Xc & Ymax = ....?
2) Xmax = ....?
Solution :
1) Xc = v02 . sin 2α
2g
= 20 . sin 600
2
2 . 10
= 400. ½√
20
= 200√
20
= 10√ m
Ymax = v02 . sin2 α
2g
= 20 . (sin 300)2
2
2 . 10
= 400. (½)2
20
= 100
20
=5m
So, the coordinate is (10√ , 5) m

6. 2) Xmax = v02 . sin 2α
g
= 20 . sin 600
2
10
= 400. ½√
10
= 200√
10
= 20√ m
Thank You