1. A person is standing on a truck moving with a constant velocity of 147 mis on a horizontal road. The man throws a ball in such a way that it returns to the truck after the truck has moved 588 m. Find the speed and the angle of projection (a) as seen from the truck, (b as seen from the road.
(a)196 m/s upward and
24-5 m/s at 53 with horizontal
(b)200 m/s upward and
30-5 m/s at 55 with
horizontal
(c)120 m/s upward and
20-2 m/s at 45 with
horizontal
Ans : (a)
2. Six particles situated at the corners of a regular hexagon of side a move at a constant speed u. Each particle maintains a direction towards the particle at the next corner. Calculate the time the particles will take to meet each other.
(a) 3 a/v
(b) 5 a/v
(c) 2 a/v
Ans : (c)
3. Suppose A and B in the previous problem change their positions in such a way that the line joining them becomes perpendicular to the direction of wind while maintaining the separation x. What will be the time lag B finds between seeing and hearing the drum beating by A?
(a) x___√v2 - u2
(b) x___√t2 - u2
Ans : (a)
4. A person standing on the top of a cliff 171 ft high has to throw a packet to his friend standing on the ground
228 ft horizontally away. If he throws the packet directly aiming at the friend with a speed of 15.0 ft/s how short will the pasket fall?
(a) 119 ft
(b) 192 ft
(c) 220 ft
Ans : (a)
5. Consider the situation of the previous problem. The man has to reach the other shore at the point directly opposite to his starting point. If he reaches the other shore somewhere else, he has to walk down to this point. Find the minimum distance that he has to walk.
(a) 5 km
(b) 2/5 km
(c) 7 km
(d) 2/3 km
Ans : (d)
6. THE geostationary orbit of the earth is at a distance of about 36000 km from the earth's surface. Find the weight of a 120-kg equipment placed in a geostationary satellite. The radius of the earth is 6400 km.
a) 18 N , b) 27 N , c) 24 N , d) 20 N ( answer = 27N )
7. Two charged particles placed at a separation of 20 cm exert 20 N of coulomb force on each other. What will be the force if the separation is increased to 25 cm ?
a) 12 N , b) 15 N , c) 13 N , d) 18 N
( answer = 13 N )
8.An athelete takes 2.0 s to reach is maximum speed of 18.0 km/h . What is the magnitude of his average acceleration ?
a) 2.5 m/s^2 ,b) 2.6 m/s^2 , c) 3.5 m/s^2 , d) 3 m/s^2
( answer = 2.5 m/s^2)
9. Find the average velocity of a projectile between the instant it crosses half the maximum height. it is projected with a speed u at an angle 'thita' with the horizontal .
a) u cos thita , horizontal in the plane of projection , b) u sin thita , horizontal in the plane o projection c) u tan thita , horizontal in the plane of projection ans :- a
10. Six particles situated at the corners of a regular hexagon of side a move at a constant speed v . Each particles maintains a direction towards the particle at the next corner. calculate the time particles will take to meet each other.
a) 3 a/v , b) 2 a/v , c) 1 a/v d) 4 a/v ( answer = 2 a/v
11.The displacement in metres of a body varies with time t in second as y = t2 – t – 2. The displacement is zero for a positive of t equal to
(a) 1 s
(b) 2 s
(c) 3 s
(d) 4 s
Answer
12.A boy starts from a point A, travels to a point B at a distance of 3 km from A and returns to A. If he takes two hours to do so, his speed is
(a) 3 km/h
(b) zero
(c) 2 km/h
(d) 1.5 km/h
13.A 180 metre long train is moving due north at a speed of 25 m/s. A small bird is flying due south, a little above the train, with a speed of 5 m/s. The time taken by the bird to cross the train is
(a) 10 s
(b) 12 s
(c) 9 s
(d) 6 s
14.A boy starts from a point A, travels to a point B at a distance of 1.5 km and returns to A. If he takes one hour to do so, his average velocity is
(a) 3 km/h
(b) zero
(c) 1.5 km/h
(d) 2 km/h
Answer
Question 5.
15.A body starts from rest and travels with uniform acceleration on a straight line. If its velocity after making a displacement of 32 m is 8 m/s, its acceleration is
(a) 1 m/s²
(b) 2 m/s²
(c) 3 m/s²
(d) 4 m/s²
16.Which one of the following is the unit of velocity?
(a) kilogram
(b) metre
(c) m/s
(d) second
17.A body starts from rest and travels for t second with uniform acceleration of 2 m/s². If the displacement made by it is 16 m, the time of travel t is
(a) 4 s
(b) 3 s
(c) 6 s
(d) 8 s
18.The dimensional formula for speed is
(a) T-1
(b) LT-1
(c) L-1T-1
(d) L-1T
19.The dimensional formula for velocity is
(a) [LT]
(b) [LT-1]
(c) [L2T]
(d) [L-1T]
20.A body starts from rest and travels with an acceleration of 2 m/s². After t seconds its velocity is 10 m/s . Then t is
(a) 10 s
(b) 5 s
(c) 20 s
(d) 6 s
21.A boy starts from a point A, travels to a point B at a distance of 1.5 km and returns to A. If he takes one hour to do so, his average velocity is
(a) 3 km/h
(b) zero
(c) 1.5 km/h
(d) 2 km/h
22.A body starts from rest. If it travels with an acceleration of 2 m/s², its displacement at the end of 3 seconds is
(a) 9 m
(b) 12 m
(c) 16 m
(d) 10 m
23.A body starts from rest and travels for five seconds to make a displacement of 25 m if it has travelled the distance with uniform acceleration a then a is
(a) 3 m/s²
(b) 4 m/s²
(c) 2 m/s²
(d) 1 m/s²
24.A boy moves on a circular distance of radius R. Starting from a point A he moves to a point B which is on the other end of the diameter AB. The ratio of the distance travelled to the displacement made by him is
(a) ∏/2
(b) ∏
(c) 2∏
(d) 4∏
25.The dimensional formula for acceleration is
(a) [LT2]
(b) [LT?2]
(c) [L2T]
(d) [L2T2]
26.A body starts from rest and travels with uniform acceleration a to make a displacement of 6 m. If its velocity after making the displacement is 6 m/s, then its uniform acceleration a is
(a) 6 m/s²
(b) 2 m/s²
(c) 3 m/s²
d) 4 m/s²
27.Which one of the following is the unit of velocity?
(a) kilogram
(b) metre
(c) m/s
(d) second
28.The displacement in metres of a body varies with time t in second as
y = t2 – t – 2. The displacement is zero for a positive of t equal to
(a) 1 s
(b) 2 s
(c) 3 s
(d) 4 s
29.The mass of a body which is equal to the ratio of the force acting on a body to the acceleration produced in the body is
(a) the gravitational mass
(b) the electromagnetic mass
(c) the internal mass
(d) the inertial mass
30.A spherical ball of mass 10-6 kg hits a wall 1000 times per second normally with a velocity of 1000 m/s and rebounds with same velocity along the initial direction. The force experienced by the wall is
(a) 1 N
(b) 4 N
(c) 2 N
(d) 8 N