Advertisements
Advertisements
Question
A body of mass 5 kg is moving with a velocity of 10 m/s. A force is applied to it so that in 25 seconds, it attains a velocity of 35 m/s. Calculate the value of the force applied.
Solution
Here, mass, m = 5kg
Let us calculate the value of acceleration by using the first equation of motion,
Given that:
initial velocity, u = 10 m/s
final velocity, v = 35 m/s
time taken, t = 25 seconds
Putting these values in the equation, we get:
v = u + at
⇒ 35 = 10 + a × 25
⇒ 35 = 10 + 25a
⇒ 35 − 10 = 25a
⇒ 25 = 25a
⇒ `a = 25/25`
⇒ `a = 1 "m/s"^2`
Now, putting m = 5 kg and a = 1 m/s2 in equation we get,
Force = mass × acceleration
Force = m × a
Force = 5 × 1
Force = 5 N
APPEARS IN
RELATED QUESTIONS
A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 metric tonnes (Hint: 1 metric tonne = 1000 kg).
The following is the distance-time table of an object in motion:
| Time in seconds | Distance in metres |
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 27 |
| 4 | 64 |
| 5 | 125 |
| 6 | 216 |
| 7 | 343 |
- What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
- What do you infer about the forces acting on the object?
Two persons manage to push a motorcar of mass 1200 kg at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of 0.2 m s−2. With what force does each person push the motorcar? (Assume that all persons push the motorcar with the same muscular effort.)
A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. Its velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. Calculate the acceleration and change in momentum. Also calculate the magnitude of the force required.
A large truck and a car, both moving with a velocity of magnitude v, have a head-on collision and both of them come to a halt after that. If the collision lasts for 1 s:-
(a) Which vehicle experiences the greater force of impact?
(b) Which vehicle experiences the greater change in momentum?
(c) Which vehicle experiences the greater acceleration?
(d)Why is the car likely to suffer more damage than the truck?
State and explain Newton’s second law of motion.
If a balloon filled with air and its mouth untied, is released with its mouth in the downward direction, it
moves upwards. Why ?
Newton’s III law is applicable
State Newton’s second law.
State Newton’s laws of motion?
