Home
Class 12
PHYSICS
Identical constant forces push two ident...

Identical constant forces push two identical cars A and B continuously from a starting line to a finish line. The cars move on a frictionless horizontal surface. If car A is initially at rest and car-B is initially moving right with speed `v_(0)`. Choose the correct statement

A

(a) Car-A has the larger change in momentum.

B

(b)Car-B has the larger change in momentum

C

(c)Both cars have the same change in momentum

D

(d)Not enough information is given decide.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the motion of the two identical cars A and B under the influence of identical constant forces. Here’s a step-by-step breakdown of the solution: ### Step 1: Understand the Initial Conditions - Car A is initially at rest, so its initial velocity \( v_{A0} = 0 \). - Car B is initially moving to the right with speed \( v_0 \), so its initial velocity \( v_{B0} = v_0 \). ### Step 2: Define the Forces and Acceleration - Both cars are subjected to the same constant force \( F \). - Since the cars are identical, they have the same mass \( m \). - The acceleration \( a \) of both cars can be expressed as: \[ a = \frac{F}{m} \] ### Step 3: Use Kinematic Equations - For Car A (initially at rest): - Final velocity \( v_A \) after traveling distance \( S \): \[ v_A^2 = v_{A0}^2 + 2aS = 0 + 2aS = 2aS \] - Therefore, \( v_A = \sqrt{2aS} \). - For Car B (initially moving): - Final velocity \( v_B \) after traveling the same distance \( S \): \[ v_B^2 = v_{B0}^2 + 2aS = v_0^2 + 2aS \] - Therefore, \( v_B = \sqrt{v_0^2 + 2aS} \). ### Step 4: Calculate Change in Momentum - Change in momentum for Car A: \[ \Delta p_A = m v_A = m \sqrt{2aS} \] - Change in momentum for Car B: \[ \Delta p_B = m v_B - m v_{B0} = m \left(\sqrt{v_0^2 + 2aS} - v_0\right) \] ### Step 5: Compare Changes in Momentum To compare \( \Delta p_A \) and \( \Delta p_B \), we need to analyze the expressions: - We know that both cars travel the same distance \( S \) and have the same acceleration \( a \). - We can see that \( v_B \) will always be greater than \( v_A \) because Car B starts with an initial speed \( v_0 \). ### Step 6: Conclusion - Since both cars are subjected to the same force and travel the same distance, but Car B starts with a higher initial velocity, the change in momentum of Car A will be greater than that of Car B. - Therefore, the correct statement is: \[ \Delta p_A > \Delta p_B \] ### Final Answer The correct statement is that Car A has a larger change in momentum than Car B.

To solve the problem, we need to analyze the motion of the two identical cars A and B under the influence of identical constant forces. Here’s a step-by-step breakdown of the solution: ### Step 1: Understand the Initial Conditions - Car A is initially at rest, so its initial velocity \( v_{A0} = 0 \). - Car B is initially moving to the right with speed \( v_0 \), so its initial velocity \( v_{B0} = v_0 \). ### Step 2: Define the Forces and Acceleration - Both cars are subjected to the same constant force \( F \). ...
Promotional Banner

Similar Questions

Explore conceptually related problems

A man of mass m is standing on a stationary flat car of mass M. The car can move without friction along horizontal rails. The man starts walking with velocity v relative to the car. Work done by him

Four cars A, B and C are moving on a levelled road. Their distance versus time graphs are shown in Fig. Choose the correct statement

A car of maas M is moving on a horizontal circular path of radius r. At an instant its speed is v and is increasing at a rate a.

Two cars A and B start moving from the same point with same velocity v=5km/minute. Car A moves towards North and car B in moving towards East. What is the relative velocity of B with respect to A ?

A car is moving along a circle with constant speed on an inclined plane as shown in diagram. Then friction force on car will be in horizontal direction at least at one point :

Speeds of two identical cars are u and 4u at at specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is

a. A rail road flat car of mass M can roll without friction along a straight horizontal track . Initially, a man of mass m is standing on the car which is moving to the right with speed v_(0) . What is the change in velocity of the car if the man runs to the left so that his speed relative to the car is v_(rel) just before he jumps off at the left end? b. If there are n men each of mass m on the car, should they all run and jump off together or should they run and jump one by one in order to give a greater velocity to the car?

Car A and car B move on a straight road and their velocity versus time graph are as shown in figure. Comparing the motion or car A in between t=0 to t =8 sec . And motion of car B in between t=0 to t=7 sec ., pick up the correct statement. .

A car moves at a constant speed on a road as shown in figure. The normal force by the road on the car is N_A and N_B when it is at the points A and B respectively .

A car is moving horizontally along a straight line with a unifrom velocity of 25 m s^-1 . A projectile is to be fired from this car in such a way that it will return to it after it has moved 100 m . The speed of the projection must be.