The area of the acceleration-displacement curve of a body gives
impulse
change in momentum per unit mass
change in KE per unit mass
total change in energy
Velocity-time curve for a body projected vertically upwards is
parabola
ellipse
hyperbola
straight line
The numerical ratio of displacement to the distance covered is always
less than one
equal to one
equal to or less than one
equal to or greater than one
A train is moving towards east and a car is along north, both with same speed. The observed direction of car to the passenger in the train is
east-north direction
west-north direction
south-east direction
None of the above
A metro train starts from rest and in 5 s achieves 108 km/h. After that it moves with constant velocity and comes to rest after travelling 45 m with uniform retardation. If total distance travelled is 395 m, find total time of travelling.
12.2 s
15.3 s
9 s
17.2 s
A police party is moving in a jeep at a constant speed v. They saw a thief at a distance x on a motorcycle which is at rest. The moment the police saw the thief, the thief started at constant acceleration a. Which of the following relations is true if the police is able to catch the thief?
v2 < αx
v2 < 2αx
v2 ≥ 2αx
v2 = αx
The engine of a jet aircraft applies a thrown force of 105 N during take off and causes the plane to attain a velocity of 1 km/s in 10 s. The mass of the plane is
102 kg
103 kg
104 kg
105 kg
A stone is weighing 1 kg and sliding on ice with a velocity of 2 m/s is stopped by friction in 10 s. The force of friction (assuming it to be constant) will be
- 20 N
-0.2 N
0.2 N
20 N
When a ceiling fan is switched on, it makes 10 revolution in the first 3 s. Assuming a uniform angular acceleration, how many rotation it will make in the next 3 s
10
20
30
40
C.
30
Angle turned in three second and θ1 s = 2 n x 10
= 20 π rad
According to the kinematic equation of Rotational motion
Now, angle turned in 6 s from the starting
= 0 +
θ2 = 80 π rad
Since angle turned between t = 3 s to t = 6 s
= 80π - 20 π
Number of revolution =
= 30
Hence Number of revolution in next 3s is 30