What should be the tension in a rope pulling vertically upward a mass of 100 kg so that starting from rest it acquires a velocity of 4 m/s in 1.5 seconds?
1278 N
1247 N
1287 N
1894 N
A train of 150 m length is going towards north direction at a speed of 10m/s. A parrot flies at the speed of 5 m/s towards south direction parallel to the railways track. The time taken by the parrot to cross the train is
12 s
8 s
15 s
10 s
A boy pushes a wall and fails to displace it. Therefore, he does
Positive work
negative work
positive but not maximum work
no work at all
An army vehicle of mass 1000 kg is moving with a velocity of 10 m/s and is acted upon by a forward force of 1000 N due to engine and a retarding force of 500 N due to friction.What will be its velocity after 10 sec ?
5 m/s
10 m/s
15 m/s
20 m/s
The rate of doing work is called
Power
impulse
torque
momentum
Two blocks P and Q are released at the top of a rough inclined plane so that P slides along the plane and Q falls down freely. Which will have higher velocity on reaching the ground?
P
Q
Both will reach the ground with same velocity
It depends on the coefficient of friction
A particle of mass m has momentum p.Its kinetic energy will be
mp
An air craft executes a horizontal loop at a speed of 720 km/h with its wings banked at 15° .What is the radius of the loop?
13 x 103 m
15.2 x 103 m
13.6 x 103 m
None of these
When the force and displacement are perpendicular to each other, the work done is
Positive
negative
Zero
maximum
The ratio of 1 joule to 1 erg is
105
107
10-7
10-5
