A car goes from a town A to another town B with a speed of 40 km/h and returns back to the town A with a speed of 60 km/h. The average speed of the car during the complete journey is -
Newton’s law of motion gives the measure of
An object will continue to accelerate until
A canon after firing recoils due to
A rocket or jet engine works on the principle of
Rate of change of momentum is equal to
When an object undergoes acceleration
When a net force acts on an object, the object will be accelerated in the direction of the force with acceleration proportional to
The action and reaction forces referred to in the third law
A driver accelerates his car first at the rate of 1.8 m/s2 and then at the rate of 1.2 m/s2. The ratio of the two forces exerted by the engine in the two cases will be
Inertia is a property of a body by virtue of which the body is
The velocity of an object is directly proportional to the time elapsed. The object has
A person travels distance pR along the circumference of a circle of radius R. Displacement of the person is
In which of the following cases the object does not possess an acceleration or retardation when it moves in
A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance s1 in the first 10 seconds and distance s2 in the next 10 seconds then,
The slope of speed-time graph gives
a particle moves with uniform positive acceleration. Its velocity-time graph will be
When the distance that an object travels is directly proportional to the length of time it is said to travel with
A body whose speed is constant
A car increases its speed from 20 km/h to 30 km/h in 10 seconds. Its acceleration is
A body moving along a straight line at 20 m/s undergoes an acceleration of -4 m/s2. After two seconds its speed will be -
When a graph of one quantity versus another results in a straight line, the quantities are
In 12 minutes a car whose speed is 35 km/h travels a distance of
A ball is thrown vertically upwards. It rises to a height of 50 m and comes back to the thrower,
The distance covered in time t by a body having initial velocity u and having a uniform acceleration a is given by s = ut + ½ at2. This result follows from -
(a) Newton’s first law
(b) Newton’s second law
(c) Newton’s third law
(d) None of these.
The initial velocity of a body is u. It is under uniform acceleration a. Its velocity v at any time t is given by -
A rider on a horseback falls back when horse starts running all of a sudden because
An athlete runs some distance before taking a long jump because
If a bus starts suddenly, the passengers in the bus will tend to fall