Question 4
A force of 25 N is acting along the North direction and a force of 12 N is acting along the South
direction on a body of mass 1.5 kg. What acceleration will the force bring in the body?
A.
9.87 m/s
2
B.
2.36 m/s
2
C.
4.67 m/s
2
D.
7.67 m/s
2
E.
8.67 m/s
2
Correct Answer: E
Explanation:
A body undergoes acceleration due to an unbalanced force. The unbalanced force here is given as
F = 25 - 12 Or F = 13N
According to Newton’s second law of motion
F = ma -------------- (1)
13 = 1.5 * a
a = 8.67 m/s
2
Therefore, E is the correct answer option.
Question 5
If a wheel is rotating with an angular velocity of 2.5 rad/s, what is the time taken by the wheel to
complete one full rotation?
A.
1.57 s
B.
2.51 s
C.
1.84 s
D.
3.52 s
E.
2.22 s
Correct Answer: B
Explanation:
Time taken to complete one rotation is known as time period. Angular velocity is related to time
period as
ω = 2π/T ---------------- (1)
Putting the values of (π = 3.14) and ω in equation 1 we get
2.5 = (2*3.14)/T
T = 2.51 s
Therefore, B is the correct answer option.
