Physics - Practice Test | ExamPrepSheets

[#481] Should cars have bumpers that collapse under impact?

(A) Yes, since the offending car should get damaged and pay for the mistake

(B) No, since it would be very expensive to get the car repaired

(C) No, since the colliding car would then ram into the occupants and kill them

(D) Yes, since they help to absorb the impact of a collision and keep the occupants safe

Correct Answer

(D) Yes, since they help to absorb the impact of a collision and keep the occupants safe

Explanation

Solution: In automobiles, a bumper is the front-most or rearmost part, ostensibly designed to allow the car to sustain an impact without damage to the vehicle’s safety systems. They are not capable of reducing injury to vehicle occupants in high-speed impacts, but are increasingly being designed to mitigate injury to pedestrians struck by cars.

[#482] When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance ?

(A) Four times

(B) Two times

(C) Half

(D) One-fourth

Correct Answer

(A) Four times

Explanation

Solution: Brake force, also known as Brake Power, is a measure of braking power of a vehicle. Suppose a car whose mass is ‘x’ and is braked from a speed of y km/hr to come to halt at a uniform retardation in z min. If the speed of the car is doubled in the same distance, then the braking force required to stop the car is four times the original speed i.e. ‘4v’. Note that all the parameters remain to be same.

[#483] The odometer guage indicates

(A) The distance travelled by a vehicle

(B) The depth of the ocean

(C) Pitch length

(D) Frequency of the wave

Correct Answer

(A) The distance travelled by a vehicle

Explanation

Solution: The odometer or the odograph is an instrument used to indicate the distance travelled by the vehicle

[#484] If a force acts upon two objects at rest, and having different masses for the same amount of time, then which one of the following will be the same for both the objects?

(A) Acceleration

(B) Kinetic Energy

(C) Velocity

(D) Momentum

Correct Answer

(D) Momentum

Explanation

Solution: If the same force is applied on two bodies of different masses for the same time, then the change produced in the momentum of the two bodies is also same .

[#485] Consider the following statements : 1. There is no net moment on a body which is in equilibrium. 2. The momentum of a body is always conserved. 3. The kinetic energy of an object is always conserved. Which of the statements given above is/are correct?

(A) 1, 2 and 3

(B) 2 and 3 only

(C) 1 and 2 only

(D) 1 only

Correct Answer

(C) 1 and 2 only

Explanation

Solution: There is no net moment on a body which is in equilibrium and the momentum of a body is always conserved both are correct.

Physics - Study Mode

[#481] Should cars have bumpers that collapse under impact?

Correct Answer

Explanation

[#482] When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance ?

Correct Answer

Explanation

[#483] The odometer guage indicates

Correct Answer

Explanation

[#484] If a force acts upon two objects at rest, and having different masses for the same amount of time, then which one of the following will be the same for both the objects?

Correct Answer

Explanation

[#485] Consider the following statements : 1. There is no net moment on a body which is in equilibrium. 2. The momentum of a body is always conserved. 3. The kinetic energy of an object is always conserved. Which of the statements given above is/are correct?

Correct Answer

Explanation