Newtons Laws 01

Front

Which of the following is not one of Newton’s laws of motion?

• The total momentum of a system of interacting bodies remains constant, providing no external force acts.
• The rate of change of momentum of a body is directly proportional to the external force acting on the body and takes place in the direction of the force.
• If a body A exerts a force on body B, then body B exerts an equal and oppositely-directed force on body A.
• A body continues in a state of rest or of uniform motion in a straight line unless acted upon by some external force.
• For every action, there is an equal and opposite reaction.

Back

The total momentum of a system of interacting bodies remains constant, providing no external force acts.

Front

An aircraft is flying straight horizontal line with constant velocity relative to the ground. What is the resultant force acting on the aircraft?

Back

zero.

Front

A parachutist of mass 80 kg is descending at a constant velocity of 3.0 m s^-1. What is the resultant force acting on the parachutist?

Back

zero.

Front

Position of pendulum bob when train starts moving with constant velocity?

Back

Remains over the mark because the motion of the train produces no additional force on the bob.

Front

A helicopter of mass 3000 kg is rising vertically with a constant velocity of 25 m s^‑1. What is the resultant force acting on the helicopter?

Back

zero

Front

A tractor of mass 1000 kg tows a trailer of mass 1000 kg. The total resistance to the motion is 4000 N and one-quarter of this resistance acts on the trailer. The tractor and trailer are moving with a constant speed of 6 m s^-1. What is the force exerted on the tractor by the tow bar?

Back

1000 N

Front

Which of the following statements best describes the weight of an object?

Back

the gravitational force acting on the object.

Front

The ball moving along the horizontal surface passes the edge at time T. Which graph shows the variation of the resultant vertical force acting on the ball with time from X to Y?

Back

Front

A rear-wheel-drive car is accelerating in the direction shown. Which diagram shows the resultant force on the rear wheels?

Back

Front

A man of mass m sits in a car that is accelerating horizontally at 0.5g. What is the magnitude of the resultant force (nearly) exerted by the seat on the man?

Back